Organic light-emitting device

ABSTRACT

An organic light-emitting device including an emission layer that is adjacent to a hole blocking layer or an electron blocking layer and includes a thermally activated delayed fluorescence (TADF) emission dopant.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from and the benefit of Korean PatentApplication No. 10-2019-0008604, filed on Jan. 23, 2019, which is herebyincorporated by reference for all purposes as if fully set forth herein.

BACKGROUND Field

Exemplary embodiments of the invention relate generally to an organiclight-emitting device.

Discussion of the Background

Organic light-emitting devices are self-emission devices that producefull-color images, and also have wide viewing angles, high contrastratios, short response times, and excellent characteristics in terms ofbrightness, driving voltage, and response speed, compared to otherdevices in the prior art.

An example of such organic light-emitting devices may include a firstelectrode on a substrate, and a hole transport region, an emissionlayer, an electron transport region, and a second electrode, which aresequentially on the first electrode. Holes provided from the firstelectrode may move toward the emission layer through the hole transportregion, and electrons provided from the second electrode may move towardthe emission layer through the electron transport region. Carriers, suchas holes and electrons, recombine in the emission layer to produceexcitons. These excitons transit from an excited state to a groundstate, thereby generating light.

The above information disclosed in this Background section is only forunderstanding of the background of the inventive concepts, and,therefore, it may contain information that does not constitute prior artSUMMARY

Exemplary embodiments of the present invention provide an organiclight-emitting device including an emission layer that is adjacent to ahole blocking layer or an electron blocking layer and includes athermally activated delayed fluorescence (TADF) emission dopant.

Additional features of the inventive concepts will be set forth in thedescription which follows, and in part will be apparent from thedescription, or may be learned by practice of the inventive concepts.

An exemplary embodiment of the present invention provides an organiclight-emitting device including: a first electrode; a second electrodefacing the first electrode; an emission layer between the firstelectrode and the second electrode; and at least one of an electronblocking layer between the first electrode and the emission layer anddirectly contacting the emission layer, and a hole blocking layerbetween the second electrode and the emission layer and directlycontacting the emission layer. The emission layer includes a host and adopant, and the dopant emits delayed fluorescence or fluorescence, theelectron blocking layer or the hole blocking layer includes a blockingmaterial, and the host, the dopant, and the blocking material satisfyEquation 1 below:

T ₁(BL)>T ₁(D)>T ₁(H),  Equation 1

-   -   where T₁(BL) is a lowest excitation triplet energy level of the        blocking material, T₁(D) is a lowest excitation triplet energy        level of the dopant, and T₁(H) is a lowest excitation triplet        energy level of the host.

The dopant may emit delayed fluorescence.

The electron blocking layer may be only between the first electrode andthe emission layer.

The hole blocking layer may be only between the second electrode and theemission layer.

The electron blocking layer may be between the first electrode and theemission layer, and the hole blocking layer may be between the secondelectrode and the emission layer.

When the blocking material is included in the electron blocking layer,the blocking material may be an electron blocking material.

When the blocking material is included in the hole blocking layer, theblocking material may be a hole blocking material.

The TADF emission region in the emission layer may be present at aninterface between the emission layer and the electron blocking layer oran interface between the emission layer and the hole blocking layer.

The dopant may be a hole trapping dopant or an electron trapping dopant.For example, when the dopant is the hole trapping dopant, the electronblocking layer may be between the first electrode and the emissionlayer, and the TADF emission region in the emission layer may be presentat an interface between the emission layer and the electron blockinglayer, and when the dopant is the electron trapping dopant, the holeblocking layer may be between the second electrode and the emissionlayer, and the TADF emission region in the emission layer may be presentat an interface between the emission layer and the hole blocking layer.

For example, when the dopant is the hole trapping dopant, a highestoccupied molecular orbital (HOMO) energy level (HOMO(D)) of the dopantand a HOMO energy level (HOMO(H)) of the host may satisfy|HOMO(H)|>|HOMO(D)|, and when the dopant is the electron trappingdopant, a lowest unoccupied molecular orbital (LUMO) energy level(LUMO(D)) of the dopant and the LUMO energy level (LUMO(H)) of the hostmay satisfy |LUMO (D)|>|LUMO (H)|.

The host, the dopant, and the blocking material may further satisfy oneor more of Equations 1-1 and 1-2:

1.0 eV>T ₁(BL)−T ₁(D)>0.01 eV  Equation 1-1

1.0 eV>T ₁(D)−T ₁(H)>0.01 eV.  Equation 1-2

The host and the dopant may further satisfy one or more of Equations1-11 and 1-12:

HOMO (D)>HOMO (H)+0.1 eV  Equation 1-11

|LUMO (D)|>|LUMO (H)|+0.1 eV.  Equation 1-12

When the host and the dopant satisfy Equation 1-11, hole trapping of thedopant strongly occurs, and light emission between the electron blockinglayer and the emission layer may be possible.

When the host and the dopant satisfy Equation 1-12, electron trapping ofthe dopant strongly occurs, and light emission between the hole blockinglayer and the emission layer may be possible.

Bonding energy between molecules of the blocking material may be lowerthan bonding energy between molecules of the host or the dopant.

The host may include a compound represented by Formula 301:

[Ar₃₀₁]_(xb11)-[(L₃₀₁)_(xb1)-R₃₀₁]_(xb21).  Formula 301

where, in Formula 301, Ar₃₀₁ may be a substituted or unsubstitutedC₅-C₆₀ carbocyclic group or a substituted or unsubstituted C₁-C₆₀heterocyclic group, xb11 may be 1, 2, or 3, L₃₀₁ may be selected from asubstituted or unsubstituted C₃-C₁₀ cycloalkylene group, a substitutedor unsubstituted C₁-C₁₀ heterocycloalkylene group, a substituted orunsubstituted C₃-C₁₀ cycloalkenylene group, a substituted orunsubstituted C₁-C₁₀ heterocycloalkenylene group, a substituted orunsubstituted C₆-C₆₀ arylene group, a substituted or unsubstitutedC₁-C₆₀ heteroarylene group, a substituted or unsubstituted divalentnon-aromatic condensed polycyclic group, and a substituted orunsubstituted divalent non-aromatic condensed heteropolycyclic group,xb1 may be an integer from 0 to 5, R₃₀₁ may be selected from deuterium,—F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, anamidino group, a hydrazino group, a hydrazono group, a substituted orunsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, asubstituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted orunsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstitutedC₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ arylgroup, a substituted or unsubstituted C₆-C₆₀ aryloxy group, asubstituted or unsubstituted C₆-C₆₀ arylthio group, a substituted orunsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstitutedmonovalent non-aromatic condensed polycyclic group, a substituted orunsubstituted monovalent non-aromatic condensed heteropolycyclic group,—Si(Q₃₀₁)(Q₃₀₂)(Q₃₀₃), —N(Q₃₀₁)(Q₃₀₂), —B(Q₃₀₁)(Q₃₀₂), —C(═O)(Q₃₀₁),—S(═O)₂(Q₃₀₁), and —P(═O)(Q₃₀₁)(Q₃₀₂), xb21 may be an integer from 1 to5, and Q₃₀₁ to Q₃₀₃ may each independently be selected from a C₁-C₁₀alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, and a naphthyl group, but the inventive concepts arenot limited thereto.

The dopant may include a compound represented by Formula 2:

where, in Formula 2, X₁₁ may be selected from O, S, N(R₁₃), andC(R₁₃)(R₁₄), X₁₂ may be selected from a single bond, O, S, N(R₁₅), andC(R₁₅)(R₁₆), Al₁ and A₁₂ may each independently be selected from aC₅-C₆₀ carbocyclic group and a C₁-C₆₀ heterocyclic group, R₁₁ to R₁₆ mayeach independently be selected from hydrogen, deuterium, —F, —Cl, —Br,—I, a hydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a substituted or unsubstitutedC₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group,a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted orunsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylgroup, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, asubstituted or unsubstituted C₆-C₆₀ aryl group, a substituted orunsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstitutedC₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroarylgroup, a substituted or unsubstituted C₁-C₆₀ heteroaryloxy group, asubstituted or unsubstituted C₁-C₆₀ heteroarylthio group, a substitutedor unsubstituted monovalent non-aromatic condensed polycyclic group, asubstituted or unsubstituted monovalent non-aromatic condensedheteropolycyclic group, —Si(Q₁)(Q₂)(Q₃), —B(Q₁)(Q₂), —N(Q₁)(Q₂),—P(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)(Q₁), —S(═O)₂(Q₁), —P(═O)(Q₁)(Q₂), and—P(═S)(Q₁)(Q₂), b11 and b12 may each independently be selected from 1,2, 3, 4, 5, and 6, and Q₁ to Q₃ may each independently be selected fromhydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group,a nitro group, an amidino group, a hydrazino group, a hydrazono group, aC₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, aC₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, aC₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a C₁-C₆₀ heteroaryloxygroup, a C₁-C₆₀ heteroarylthio group, a monovalent non-aromaticcondensed polycyclic group, a monovalent non-aromatic condensedheteropolycyclic group, a biphenyl group, and a terphenyl group.

The dopant may include a compound represented by Formula 3:

where, in Formula 3, X₂₁ may be N or C(R₂₁), X₂₂ may be N or C(R₂₂), X₂₃may be N or C(R₂₃), X₂₄ may be N or C(R₂₄), X₂₅ may be N or C(R₂₅), X₂₆may be N or C(R₂₆), and at least one selected from X₂₁ to X₂₆ may be N,R₂₁ to R₂₆ may each independently be selected from hydrogen, deuterium,a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted orunsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstitutedmonovalent non-aromatic condensed polycyclic group, and a substituted orunsubstituted monovalent non-aromatic condensed heteropolycyclic group,at least one selected from R₂₁ to R₂₆ may be selected from a substitutedor unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstitutedC₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalentnon-aromatic condensed polycyclic group, and a substituted orunsubstituted monovalent non-aromatic condensed heteropolycyclic group.

The electron blocking layer may include a blocking material, and theblocking material may include a compound represented by Formula 2:

where, in Formula 2, X₁₁ may be selected from O, S, N(R₁₃), andC(R₁₃)(R₁₄), X₁₂ may be selected from a single bond, O, S, N(R₁₅), andC(R₁₅)(R₁₆), A₁₁ and A₁₂ may each independently be selected from aC₅-C₆₀ carbocyclic group and a C₁-C₆₀ heterocyclic group, R₁₁ to R₁₆ mayeach independently be selected from hydrogen, deuterium, —F, —Cl, —Br,—I, a hydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a substituted or unsubstitutedC₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group,a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted orunsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylgroup, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, asubstituted or unsubstituted C₆-C₆₀ aryl group, a substituted orunsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstitutedC₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroarylgroup, a substituted or unsubstituted C₁-C₆₀ heteroaryloxy group, asubstituted or unsubstituted C₁-C₆₀ heteroarylthio group, a substitutedor unsubstituted monovalent non-aromatic condensed polycyclic group, asubstituted or unsubstituted monovalent non-aromatic condensedheteropolycyclic group, —Si(Q₁)(Q₂)(Q₃), —B(Q₁)(Q₂), —N(Q₁)(Q₂),—P(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)(Q₁), —S(═O)₂(Q₁), —P(═O)(Q₁)(Q₂), and—P(═S)(Q₁)(Q₂), b11 and b12 may each independently be selected from 1,2, 3, 4, 5, and 6, and Q₁ to Q₃ may each independently be selected fromhydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group,a nitro group, an amidino group, a hydrazino group, a hydrazono group, aC₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, aC₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, aC₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a C₁-C₆₀ heteroaryloxygroup, a C₁-C₆₀ heteroarylthio group, a monovalent non-aromaticcondensed polycyclic group, a monovalent non-aromatic condensedheteropolycyclic group, a biphenyl group, and a terphenyl group.

The hole blocking layer may include a blocking material, and theblocking material may include a compound represented by Formula 3:

where, in Formula 3, X₂₁ may be N or C(R₂₁), X₂₂ may be N or C(R₂₂), X₂₃may be N or C(R₂₃), X₂₄ may be N or C(R₂₄), X₂₅ may be N or C(R₂₅), X₂₆may be N or C(R₂₆), and at least one selected from X₂₁ to X₂₆ may be N,R₂₁ to R₂₆ may each independently be selected from hydrogen, deuterium,a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted orunsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstitutedmonovalent non-aromatic condensed polycyclic group, and a substituted orunsubstituted monovalent non-aromatic condensed heteropolycyclic group,and at least one selected from R₂₁ to R₂₆ may be selected from asubstituted or unsubstituted C₆-C₆₀ aryl group, a substituted orunsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstitutedmonovalent non-aromatic condensed polycyclic group, and a substituted orunsubstituted monovalent non-aromatic condensed heteropolycyclic group.

The organic light-emitting device may further include a hole transportregion between the first electrode and the emission layer, and the holetransport region may include a hole transport material.

The organic light-emitting device may further include an electrontransport region between the emission layer and the second electrode,and the electron transport region may include an electron transportmaterial.

A ratio of a delayed fluorescence component to total emission componentsemitted from the emission layer may be greater than or equal to 50%.

Another exemplary embodiment of the present invention provides a displayapparatus including: a thin-film transistor including a sourceelectrode, a drain electrode, and an active layer; and the organiclight-emitting device described above. The first electrode of theorganic light-emitting device is electrically connected to one selectedfrom the source electrode and the drain electrode of the thin-filmtransistor.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate exemplary embodiments of theinvention, and together with the description serve to explain theinventive concepts.

FIG. 1 is a schematic view of an organic light-emitting device accordingto an exemplary embodiment.

FIG. 2 is a schematic view of an organic light-emitting device accordingto another exemplary embodiment.

FIG. 3 is a schematic view of an organic light-emitting device accordingto another exemplary embodiment.

DETAILED DESCRIPTION

In the following description, for the purposes of explanation, numerousspecific details are set forth in order to provide a thoroughunderstanding of various exemplary embodiments of the invention. As usedherein “embodiments” are non-limiting examples of devices or methodsemploying one or more of the inventive concepts disclosed herein. It isapparent, however, that various exemplary embodiments may be practicedwithout these specific details or with one or more equivalentarrangements. In other instances, well-known structures and devices areshown in block diagram form in order to avoid unnecessarily obscuringvarious exemplary embodiments. Further, various exemplary embodimentsmay be different, but do not have to be exclusive. For example, specificshapes, configurations, and characteristics of an exemplary embodimentmay be used or implemented in another exemplary embodiment withoutdeparting from the inventive concepts.

Unless otherwise specified, the illustrated exemplary embodiments are tobe understood as providing exemplary features of varying detail of someways in which the inventive concepts may be implemented in practice.Therefore, unless otherwise specified, the features, components,modules, layers, films, panels, regions, and/or aspects, etc.(hereinafter individually or collectively referred to as “elements”), ofthe various embodiments may be otherwise combined, separated,interchanged, and/or rearranged without departing from the inventiveconcepts.

In the accompanying drawings, the size and relative sizes of elementsmay be exaggerated for clarity and/or descriptive purposes. When anexemplary embodiment may be implemented differently, a specific processorder may be performed differently from the described order. Forexample, two consecutively described processes may be performedsubstantially at the same time or performed in an order opposite to thedescribed order. Also, like reference numerals denote like elements.

When an element, such as a layer, is referred to as being “on,”“connected to,” or “coupled to” another element or layer, it may bedirectly on, connected to, or coupled to the other element or layer orintervening elements or layers may be present. When, however, an elementor layer is referred to as being “directly on,” “directly connected to,”or “directly coupled to” another element or layer, there are nointervening elements or layers present. To this end, the term“connected” may refer to physical, electrical, and/or fluid connection,with or without intervening elements. Further, the D1-axis, the D2-axis,and the D3-axis are not limited to three axes of a rectangularcoordinate system, such as the x, y, and z-axes, and may be interpretedin a broader sense. For example, the D1-axis, the D2-axis, and theD3-axis may be perpendicular to one another, or may represent differentdirections that are not perpendicular to one another. For the purposesof this disclosure, “at least one of X, Y, and Z” and “at least oneselected from the group consisting of X, Y, and Z” may be construed as Xonly, Y only, Z only, or any combination of two or more of X, Y, and Z,such as, for instance, XYZ, XYY, YZ, and ZZ. As used herein, the term“and/or” includes any and all combinations of one or more of theassociated listed items.

Although the terms “first,” “second,” etc. may be used herein todescribe various types of elements, these elements should not be limitedby these terms. These terms are used to distinguish one element fromanother element. Thus, a first element discussed below could be termed asecond element without departing from the teachings of the disclosure.

Spatially relative terms, such as “beneath,” “below,” “under,” “lower,”“above,” “upper,” “over,” “higher,” “side” (e.g., as in “sidewall”), andthe like, may be used herein for descriptive purposes, and, thereby, todescribe one elements relationship to another element(s) as illustratedin the drawings. Spatially relative terms are intended to encompassdifferent orientations of an apparatus in use, operation, and/ormanufacture in addition to the orientation depicted in the drawings. Forexample, if the apparatus in the drawings is turned over, elementsdescribed as “below” or “beneath” other elements or features would thenbe oriented “above” the other elements or features. Thus, the exemplaryterm “below” can encompass both an orientation of above and below.Furthermore, the apparatus may be otherwise oriented (e.g., rotated 90degrees or at other orientations), and, as such, the spatially relativedescriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particularembodiments and is not intended to be limiting. As used herein, thesingular forms, “a,” “an,” and “the” are intended to include the pluralforms as well, unless the context clearly indicates otherwise. Moreover,the terms “comprises,” “comprising,” “includes,” and/or “including,”when used in this specification, specify the presence of statedfeatures, integers, steps, operations, elements, components, and/orgroups thereof, but do not preclude the presence or addition of one ormore other features, integers, steps, operations, elements, components,and/or groups thereof. It is also noted that, as used herein, the terms“substantially,” “about,” and other similar terms, are used as terms ofapproximation and not as terms of degree, and, as such, are utilized toaccount for inherent deviations in measured, calculated, and/or providedvalues that would be recognized by one of ordinary skill in the art.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this disclosure is a part. Terms,such as those defined in commonly used dictionaries, should beinterpreted as having a meaning that is consistent with their meaning inthe context of the relevant art and should not be interpreted in anidealized or overly formal sense, unless expressly so defined herein.

A sample in which a compound was deposited on a quartz substrate to athickness of 500 Å was prepared, a photoluminescence spectrum of thesample was obtained at a temperature of 4K, and a wavelength of thefirst peak of the photoluminescence spectrum (a wavelength having theshortest wavelength or an onset wavelength of the peak) was analyzed tocalculate a lowest excitation triplet energy level (T₁ energy level).

The term “organic layer” as used herein refers to a single layer and/ora plurality of layers between an anode and a cathode of an organiclight-emitting device. A material included in the “organic layer” is notlimited to an organic material.

The expression “(an organic layer) includes at least one compoundrepresented by Formula 1” as used herein may include a case in which“(an organic layer) includes identical compounds represented by Formula1” and a case in which “(an organic layer) includes two or moredifferent compounds represented by Formula 1”.

Hereinafter, exemplary embodiments of the inventive concepts will bedescribed in detail with reference to the attached drawings.

[Description of FIGS. 1 to 3]

FIGS. 1 to 3 are each a schematic cross-sectional view of an organiclight-emitting device 10, 20, or 30 according to an exemplaryembodiment. The organic light-emitting device 10, 20, or 30 includes afirst electrode 110, an emission layer 150, and a second electrode 190.

Referring to FIGS. 1 to 3, an organic light-emitting device 10, 20, or30 may include: a first electrode 110; a second electrode 190 facing thefirst electrode 110; an emission layer 150 between the first electrode110 and the second electrode 190; and an electron blocking layer 131between the first electrode 110 and the emission layer 150 and directlycontacting the emission layer 150, and/or a hole blocking layer betweenthe second electrode 190 and the emission layer 150 and directlycontacting the emission layer 150. The emission layer 150 may include ahost and a dopant, the dopant may emit delayed fluorescence orfluorescence, the electron blocking layer 131 or the hole blocking layer132 may include a blocking material, and the host, the dopant, and theblocking material may satisfy Equation 1:

T ₁(BL)>T ₁(D)>T ₁(H).  Equation 1

In Equation 1, T₁(BL) is a lowest excitation triplet energy level of theblocking material, T₁(D) is a lowest excitation triplet energy level ofthe dopant, and T₁(H) is a lowest excitation triplet energy level of thehost.

As described above, when the emission layer 150 is disposed to directlycontact the electron blocking layer 131 or the hole blocking layer 132and a lowest excitation triplet energy level (E(T₁)) of the blockingmaterial included in the electron blocking layer 131 or the holeblocking layer 132 is higher than a lowest excitation triplet energylevel (E(T₁)) of the host or the dopant included in the emission layer150, thermally activated delayed fluorescence (TADF) emission may appearonly at an interface between the emission layer 150 and the electronblocking layer 131 or an interface between the emission layer 150 andthe hole blocking layer 132. The efficiency may be increased throughTADF emission at these interfaces, as compared with an existingfluorescent light-emitting diode.

In addition, since the host having a relatively lower E(T₁) than theblocking material is used, it is possible to reduce triplet excitonconcentration due to triplet quenching. The lifespan of the device maybe improved by positioning the blocking material having a relativelyhigh E(T₁) at the outside of the emission layer 150.

Furthermore, the organic light-emitting device may reduce a ratio atwhich excitons generated in the emission layer 150 move to the holetransport region without participating in light emission, therebyincreasing the triplet concentration in the emission layer 150.Therefore, the efficiency of the organic light-emitting device may beimproved.

In addition, the organic light-emitting device may substantially blockthe movement of the excitons generated in the emission layer 150 to theelectron transport region without participating in light emission,thereby increasing the triplet concentration in the emission layer 150.Therefore, the efficiency of the organic light-emitting device may beimproved.

In order to obtain the above-described effect, the emission layer 150and the hole blocking layer 132 or the electron blocking layer 131 mustdirectly contact each other, and another layer must not be between theemission layer 150 and the hole blocking layer 132 or between theemission layer and the electron blocking layer 131.

The dopant that emits delayed fluorescence may be at an interfacebetween the emission layer 150 and the electron blocking layer 131 orthe hole blocking layer 132. Even in the same structure as the dopant,if the dopant is not at the interface between the emission layer 150 andthe electron blocking layer 131 or the hole blocking layer 132,fluorescence other than delayed fluorescence may be emitted. Therefore,TADF characteristics may be exhibited only at the interface between theemission layer 150 and the electron blocking layer 131 or the holeblocking layer 132.

For example, i) as illustrated in FIG. 1, the electron blocking layer131 may be only between the first electrode 110 and the emission layer150; ii) as illustrated in FIG. 2, the hole blocking layer 132 may beonly between the second electrode 190 and the emission layer 150; oriii) as illustrated in FIG. 3, the electron blocking layer 131 may bebetween the first electrode 110 and the emission layer 150, and the holeblocking layer 132 may be between the second electrode 190 and theemission layer 150.

For example, a TADF emission region in the emission layer 150 may bepresent at the interface between the emission layer 150 and the electronblocking layer 131 or at the interface between the emission layer 150and the hole blocking layer 132.

At this time, the dopant may emit delayed fluorescence. For example, thedopant may emit TADF.

In an exemplary embodiment, the dopant may be a hole trapping dopant oran electron trapping dopant. The “hole trapping dopant” may be acompound having a HOMO energy level and a LUMO energy level higher thanthose of the host, and the “electron trapping dopant” may be a compoundhaving a HOMO energy level and a LUMO energy level lower than those ofthe host.

When the dopant is the hole trapping dopant, the electron blocking layer131 may be between the first electrode 110 and the emission layer 150,and the TADF emission region in the emission layer 150 may be present atthe interface between the emission layer 150 and the electron blockinglayer 131. When the dopant is the electron trapping dopant, the holeblocking layer 132 may be between the second electrode 190 and theemission layer 150, and the TADF emission region in the emission layer150 may be present at the interface between the emission layer 150 andthe hole blocking layer 132. Even when the dopant is the hole trappingdopant, the hole blocking layer 132 may be between the second electrode190 and the emission layer 150, and even when the dopant is the electrontrapping dopant, the electron blocking layer 131 may be between thefirst electrode 110 and the emission layer 150.

In addition, when the dopant is the hole trapping dopant, the HOMOenergy level (HOMO(D)) of the dopant and the HOMO energy level (HOMO(H))of the host may satisfy |HOMO(H)|>|HOMO(D)|, and when the dopant is theelectron trapping dopant. the LUMO energy level (LUMO(D)) of the dopantand the LUMO energy level (LUMO(H)) of the host may satisfy|LUMO(D)|>|LUMO(H)|.

In an exemplary embodiment, the host, the dopant, and the blockingmaterial may further satisfy one or more selected from Equations 1-1 and1-2:

1.0 eV>T ₁(BL)−T ₁(D)>0.01 eV  Equation 1-1

1.0 eV>T ₁(D)−T ₁(H)>0.01 eV.  Equation 1-2

In the organic light-emitting device satisfying Equations 1-1 and 1-2,some of the excitons generated in the emission layer 150 may be quenchedwithout participating in light emission. Therefore, a deterioration ratecaused by triplet-triplet annihilation (TTA) or triplet polaronquenching (TPQ) with adjacent organic layers (the emission layer, theelectron blocking layer, the hole blocking layer) may be reduced,thereby improving the lifespan of the organic light-emitting device.

In an exemplary embodiment, the host and the dopant may further satisfyone or more selected from Equations 1-11 and 1-12:

HOMO(D)>HOMO(H)+0.1 eV  Equation 1-11

|LUMO(D)|>|LUMO(H)|+0.1 eV  Equation 1-12

When the host and the dopant satisfy Equation 1-11, hole trapping of thedopant strongly occurs, and light emission between the electron blockinglayer and the emission layer may be possible.

When the host and the dopant satisfy Equation 1-12, electron trapping ofthe dopant strongly occurs, and light emission between the hole blockinglayer and the emission layer may be possible.

In addition, when the host and the dopant satisfy Equation 1-2, theefficiency of the device may be significantly reduced by T₁ of the host.At this time, when the host and the dopant further satisfy Equations1-11 or 1-12, the efficiency reduction width may be improved, and thelifespan of the device may be remarkably improved.

For example, bonding energy between molecules of the blocking materialmay be lower than bonding energy between molecules of the host or thedopant. Since the blocking material having relatively low bonding energybetween the molecules is outside the emission layer 150 including thehost or the dopant, the lifespan of the device may be improved.

Hereinafter, components of the organic light-emitting device accordingto exemplary embodiments will be described in detail with reference toFIGS. 1 to 3.

[First Electrode 110]

Referring to FIGS. 1 to 3, a substrate may be additionally under thefirst electrode 110 or above the second electrode 190. The substrate maybe a glass substrate or a plastic substrate, each having excellentmechanical strength, thermal stability, transparency, surfacesmoothness, ease of handling, and water resistance.

The first electrode 110 may be formed by depositing or sputtering amaterial for forming the first electrode 110 on the substrate. When thefirst electrode 110 is an anode, the material for a first electrode maybe selected from materials with a high work function to facilitate holeinjection.

The first electrode 110 may be a reflective electrode, asemi-transmissive electrode, or a transmissive electrode. When the firstelectrode 110 is a transmissive electrode, a material for forming afirst electrode may be selected from indium tin oxide (ITO), indium zincoxide (IZO), tin oxide (SnO₂), zinc oxide (ZnO), and any combinationsthereof, but embodiments of the present disclosure are not limitedthereto. In one or more embodiments, when the first electrode 110 is asemi-transmissive electrode or a reflectable electrode, a material forforming a first electrode may be selected from magnesium (Mg), silver(Ag), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca),magnesium-indium (Mg—In), magnesium-silver (Mg—Ag), and any combinationsthereof, but the inventive concepts are not limited thereto.

The first electrode 110 may have a single-layered structure, or amulti-layered structure including two or more layers. For example, thefirst electrode 110 may have a three-layered structure of ITO/Ag/ITO,but the structure of the first electrode 110 is not limited thereto.

[Organic Layer]

The organic layer may be on the first electrode 110. The organic layermay include an emission layer 150.

The organic layer may further include a hole transport region betweenthe first electrode 110 and the emission layer 150, and an electrontransport region between the emission layer 150 and the second electrode190.

[Hole Transport Region in Organic Layer]

The hole transport region may have i) a single-layered structureincluding a single layer including a single material, ii) asingle-layered structure including a single layer including a pluralityof different materials, or iii) a multi-layered structure having aplurality of layers including a plurality of different materials.

The hole transport region may include at least one layer selected froman electron blocking layer 131, a hole injection layer, a hole transportlayer, and an emission auxiliary layer.

For example, the hole transport region may have a single-layeredstructure including a single layer including a plurality of differentmaterials, or a multi-layered structure having a hole injectionlayer/hole transport layer structure, a hole injection layer/holetransport layer/emission auxiliary layer structure, a hole injectionlayer/emission auxiliary layer structure, a hole injection layer/holetransport layer/electron blocking layer 131 structure, a hole injectionlayer/hole transport layer/emission auxiliary layer/electron blockinglayer 131 structure, a hole injection layer/emission auxiliarylayer/electron blocking layer 131 structure, or a hole transportlayer/emission auxiliary layer/electron blocking layer 131 structure,wherein for each structure, constituting layers are sequentially stackedfrom the first electrode 110 in this stated order, but the structure ofthe hole transport region is not limited thereto.

The hole transport region may include at least one selected fromm-MTDATA, TDATA, 2-TNATA, NPB(NPD), β-NPB, TPD, Spiro-TPD, Spiro-NPB,methylated-NPB, TAPC, HMTPD, 4,4′,4″-tris(N-carbazolyl)triphenylamine(TCTA), polyaniline/dodecylbenzenesulfonic acid (PANI/DBSA),poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS),polyaniline/camphor sulfonic acid (PANI/CSA),polyaniline/poly(4-styrenesulfonate) (PANI/PSS), a compound representedby Formula 201, and a compound represented by Formula 202:

In Formulae 201 and 202, L₂₀₁ to L₂₀₄ may each independently be selectedfrom a substituted or unsubstituted C₃-C₁₀ cycloalkylene group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkylene group, asubstituted or unsubstituted C₃-C₁₀ cycloalkenylene group, a substitutedor unsubstituted C₁-C₁₀ heterocycloalkenylene group, a substituted orunsubstituted C₆-C₆₀ arylene group, a substituted or unsubstitutedC₁-C₆₀ heteroarylene group, a substituted or unsubstituted divalentnon-aromatic condensed polycyclic group, and a substituted orunsubstituted divalent non-aromatic condensed heteropolycyclic group,L₂₀₅ may be selected from *—O—*′, *—S—*′, *—N(Q₂₀₁)-*′, a substituted orunsubstituted C₁-C₂₀ alkylene group, a substituted or unsubstitutedC₂-C₂₀ alkenylene group, a substituted or unsubstituted C₃-C₁₀cycloalkylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylenegroup, a substituted or unsubstituted divalent non-aromatic condensedpolycyclic group, and a substituted or unsubstituted divalentnon-aromatic condensed heteropolycyclic group, xa1 to xa4 may eachindependently be an integer from 0 to 3, xa5 may be an integer from 1 to10, and R₂₀₁ to R₂₀₄ and Q₂₀₁ may each independently be selected from asubstituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted orunsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted orunsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstitutedC₁-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, asubstituted or unsubstituted C₆-C₆₀ arylthio group, a substituted orunsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstitutedmonovalent non-aromatic condensed polycyclic group, and a substituted orunsubstituted monovalent non-aromatic condensed heteropolycyclic group.

For example, in Formula 202, R₂₀₁ and R₂₀₂ may optionally be linked viaa single bond, a dimethyl-methylene group, or a diphenyl-methylenegroup, and R₂₀₃ and R₂₀₄ may optionally be linked via a single bond, adimethyl-methylene group, or a diphenyl-methylene group.

In an exemplary embodiment, in Formulae 201 and 202, L₂₀₁ to L₂₀₅ mayeach independently be selected from: a phenylene group, a pentalenylenegroup, an indenylene group, a naphthylene group, an azulenylene group, aheptalenylene group, an indacenylene group, an acenaphthylene group, afluorenylene group, a spiro-bifluorenylene group, a benzofluorenylenegroup, a dibenzofluorenylene group, a phenalenylene group, aphenanthrenylene group, an anthracenylene group, a fluoranthenylenegroup, a triphenylenylene group, a pyrenylene group, a chrysenylenegroup, a naphthacenylene group, a picenylene group, a perylenylenegroup, a pentaphenylene group, a hexacenylene group, a pentacenylenegroup, a rubicenylene group, a coronenylene group, an ovalenylene group,a thiophenylene group, a furanylene group, a carbazolylene group, anindolylene group, an isoindolylene group, a benzofuranylene group, abenzothiophenylene group, a dibenzofuranylene group, adibenzothiophenylene group, a benzocarbazolylene group, adibenzocarbazolylene group, a dibenzosilolylene group, and apyridinylene group; and a phenylene group, a pentalenylene group, anindenylene group, a naphthylene group, an azulenylene group, aheptalenylene group, an indacenylene group, an acenaphthylene group, afluorenylene group, a spiro-bifluorenylene group, a benzofluorenylenegroup, a dibenzofluorenylene group, a phenalenylene group, aphenanthrenylene group, an anthracenylene group, a fluoranthenylenegroup, a triphenylenylene group, a pyrenylene group, a chrysenylenegroup, a naphthacenylene group, a picenylene group, a perylenylenegroup, a pentaphenylene group, a hexacenylene group, a pentacenylenegroup, a rubicenylene group, a coronenylene group, an ovalenylene group,a thiophenylene group, a furanylene group, a carbazolylene group, anindolylene group, an isoindolylene group, a benzofuranylene group, abenzothiophenylene group, a dibenzofuranylene group, adibenzothiophenylene group, a benzocarbazolylene group, adibenzocarbazolylene group, a dibenzosilolylene group, and apyridinylene group, each substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexylgroup, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group,a phenyl group, a biphenyl group, a terphenyl group, a phenyl groupsubstituted with a C₁-C₁₀ alkyl group, a phenyl group substituted with—F, a pentalenyl group, an indenyl group, a naphthyl group, an azulenylgroup, a heptalenyl group, an indacenyl group, an acenaphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, ananthracenyl group, a fluoranthenyl group, a triphenylenyl group, apyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group,a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a rubicenyl group, a coronenyl group, an ovalenyl group, athiophenyl group, a furanyl group, a carbazolyl group, an indolyl group,an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, adibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolylgroup, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinylgroup, —Si(Q₃₁)(Q₃₂)(Q₃₃), and —N(Q₃₁)(Q₃₂), and Q₃₁ to Q₃₃ may eachindependently be selected from a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxygroup, a phenyl group, a biphenyl group, a terphenyl group, and anaphthyl group.

In an exemplary embodiment, xa1 to xa4 may each independently be 0, 1,or 2.

In an exemplary embodiment, xa5 may be 1, 2, 3, or 4.

In an exemplary embodiment, R₂₀₁ to R₂₀₄ and Q₂₀₁ may each independentlybe selected from: a phenyl group, a biphenyl group, a terphenyl group, apentalenyl group, an indenyl group, a naphthyl group, an azulenyl group,a heptalenyl group, an indacenyl group, an acenaphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, ananthracenyl group, a fluoranthenyl group, a triphenylenyl group, apyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group,a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a rubicenyl group, a coronenyl group, an ovalenyl group, athiophenyl group, a furanyl group, a carbazolyl group, an indolyl group,an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, adibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolylgroup, a dibenzocarbazolyl group, a dibenzosilolyl group, and apyridinyl group; and a phenyl group, a biphenyl group, a terphenylgroup, a pentalenyl group, an indenyl group, a naphthyl group, anazulenyl group, a heptalenyl group, an indacenyl group, an acenaphthylgroup, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenylgroup, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenylgroup, an anthracenyl group, a fluoranthenyl group, a triphenylenylgroup, a pyrenyl group, a chrysenyl group, a naphthacenyl group, apicenyl group, a perylenyl group, a pentaphenyl group, a hexacenylgroup, a pentacenyl group, a rubicenyl group, a coronenyl group, anovalenyl group, a thiophenyl group, a furanyl group, a carbazolyl group,an indolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, and a pyridinyl group, each substituted with atleast one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, acyano group, a nitro group, an amidino group, a hydrazino group, ahydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, acyclopentyl group, a cyclohexyl group, a cycloheptyl group, acyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenylgroup, a terphenyl group, a phenyl group substituted with a C₁-C₁₀ alkylgroup, a phenyl group substituted with —F, a pentalenyl group, anindenyl group, a naphthyl group, an azulenyl group, a heptalenyl group,an indacenyl group, an acenaphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenylgroup, a phenalenyl group, a phenanthrenyl group, an anthracenyl group,a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, achrysenyl group, a naphthacenyl group, a picenyl group, a perylenylgroup, a pentaphenyl group, a hexacenyl group, a pentacenyl group, arubicenyl group, a coronenyl group, an ovalenyl group, a thiophenylgroup, a furanyl group, a carbazolyl group, an indolyl group, anisoindolyl group, a benzofuranyl group, a benzothiophenyl group, adibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolylgroup, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinylgroup, —Si(Q₃₁)(Q₃₂)(Q₃₃), and —N(Q₃₁)(Q₃₂), where Q₃₁ to Q₃₃ are thesame as described above.

In an exemplary embodiment, in Formula 201, at least one selected fromR₂₀₁ to R₂₀₃ may each independently be selected from: a fluorenyl group,a spiro-bifluorenyl group, a carbazolyl group, a dibenzofuranyl group,and a dibenzothiophenyl group; and a fluorenyl group, aspiro-bifluorenyl group, a carbazolyl group, a dibenzofuranyl group, anda dibenzothiophenyl group, each substituted with at least one selectedfrom deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, anitro group, an amidino group, a hydrazino group, a hydrazono group, aC₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, acyclohexyl group, a cycloheptyl group, a cyclopentenyl group, acyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group,a phenyl group substituted with a C₁-C₁₀ alkyl group, a phenyl groupsubstituted with —F, a naphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a carbazolyl group, a dibenzofuranyl group, anda dibenzothiophenyl group, but embodiments of the present disclosure arenot limited thereto.

In an exemplary embodiment, in Formula 202, R₂₀₁ and R₂₀₂ may be linkedvia a single bond, and/or R₂₀₃ and R₂₀₄ may be linked via a single bond.

In an exemplary embodiment, in Formula 202, at least one selected fromR₂₀₁ to R₂₀₄ may be selected from: a carbazolyl group; and a carbazolylgroup substituted with at least one selected from deuterium, —F, —Cl,—Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidinogroup, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, aC₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, acycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenylgroup, a biphenyl group, a terphenyl group, a phenyl group substitutedwith a C₁-C₁₀ alkyl group, a phenyl group substituted with —F, anaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, acarbazolyl group, a dibenzofuranyl group, and a dibenzothiophenyl group,but inventive concepts are not limited thereto.

The compound represented by Formula 201 may be represented by Formula201A:

For example, the compound represented by Formula 201 may be representedby Formula 201A(1), but the inventive concepts are not limited thereto:

In an exemplary embodiment, the compound represented by Formula 201 maybe represented by Formula 201A-1, but the inventive concepts are notlimited thereto:

In an exemplary embodiment, the compound represented by Formula 202 maybe represented by Formula 202A:

In an exemplary embodiment, the compound represented by Formula 202 maybe represented by Formula 202A-1:

In Formulae 201A, 201A(1), 201A-1, 202A, and 202A-1, L₂₀₁ to L₂₀₃, xa1to xa3, xa5, and R₂₀₂ to R₂₀₄ are the same as described above, R₂₁₁ andR₂₁₂ may be the same as defined in connection with R₂₀₃, and R₂₁₃ toR₂₁₇ may each independently be selected from hydrogen, deuterium, —F,—Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidinogroup, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, aC₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, acycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenylgroup, a biphenyl group, a terphenyl group, a phenyl group substitutedwith a C₁-C₁₀ alkyl group, a phenyl group substituted with —F, apentalenyl group, an indenyl group, a naphthyl group, an azulenyl group,a heptalenyl group, an indacenyl group, an acenaphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, ananthracenyl group, a fluoranthenyl group, a triphenylenyl group, apyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group,a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a rubicenyl group, a coronenyl group, an ovalenyl group, athiophenyl group, a furanyl group, a carbazolyl group, an indolyl group,an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, adibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolylgroup, a dibenzocarbazolyl group, a dibenzosilolyl group, and apyridinyl group.

The hole transport region may include at least one compound selectedfrom Compounds HT1 to HT39, but the inventive concepts are not limitedthereto:

A thickness of the hole transport region may be in a range of about 100Å to about 10,000 Å, for example, about 100 Å to about 1,000 Å. When thehole transport region includes at least one selected from a holeinjection layer and a hole transport layer, the thickness of the holeinjection layer may be in a range of about 100 Å to about 9,000 Å, andfor example, about 100 Å to about 1,000 Å, and the thickness of the holetransport layer may be in a range of about 50 Å to about 2,000 Å, andfor example, about 100 Å to about 1,500 Å. When the thicknesses of thehole transport region, the hole injection layer, and the hole transportlayer are within these ranges, satisfactory hole transportingcharacteristics may be obtained without a substantial increase indriving voltage.

The emission auxiliary layer may increase light-emission efficiency bycompensating for an optical resonance distance according to thewavelength of light emitted by an emission layer 150, and the electronblocking layer 131 may block the flow of electrons from an electrontransport region. The emission auxiliary layer and the electron blockinglayer may include the materials as described above.

[p-Dopant]

The hole transport region may further include, in addition to thesematerials, a charge-generation material for the improvement ofconductive properties. The charge-generation material may behomogeneously or non-homogeneously dispersed in the hole transportregion.

The charge-generation material may be, for example, a p-dopant.

In an exemplary embodiment, the p-dopant may have a lowest unoccupiedmolecular orbital (LUMO) energy level of −3.5 eV or less.

The p-dopant may include at least one selected from a quinonederivative, a metal oxide, and a cyano group-containing compound, butthe inventive concepts are not limited thereto.

For example, the p-dopant may include at least one selected from: aquinone derivative, such as tetracyanoquinodimethane (TCNQ) or2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ); a metaloxide, such as tungsten oxide or molybdenum oxide;1,4,5,8,9,12-hexaazatriphenylene-hexacarbonitrile (HAT-CN); and acompound represented by Formula 221 below, but the inventive conceptsare not limited thereto:

In Formula 221, R₂₂₁ to R₂₂₃ may each independently be selected from asubstituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted orunsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted orunsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstitutedC₁-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀aryl group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, asubstituted or unsubstituted monovalent non-aromatic condensedpolycyclic group, and a substituted or unsubstituted monovalentnon-aromatic condensed heteropolycyclic group, wherein at least oneselected from R₂₂₁ to R₂₂₃ may have at least one substituent selectedfrom a cyano group, —F, —Cl, —Br, —I, a C₁-C₂₀ alkyl group substitutedwith —F, a C₁-C₂₀ alkyl group substituted with —Cl, a C₁-C₂₀ alkyl groupsubstituted with —Br, and a C₁-C₂₀ alkyl group substituted with —I.

The electron blocking material included in the electron blocking layermay satisfy 2.5 eV≤T₁(BL)≤3.5 eV, but the inventive concepts are notlimited thereto. When the electron blocking material satisfies thisrange, excitons are substantially trapped in the emission layer, andexcitons may sufficiently participate in light emission.

The electron blocking material may include, for example, carbazole-basedderivatives such as N-phenylcarbazole or polyvinylcarbazole,fluorine-based derivatives,N,N′-bis(3-methylphenyl)-N,N′-diphenyl-[1,1-biphenyl]-4,4′-diamine(TPD), triphenylamine derivatives such as4,4′,4″-tris(N-carbazolyl)triphenylamine (TCTA),N,N′-di(naphthalene-1-yl)-N,N′-diplienyl-benzidine (NPD),4,4′-cyclohexylidene bis[N,N-bis(4-methylphenyl)benzenamine] (TAPC),4,4′-Bis[N,N′-(3-tolyl)amino]-3,3′-dimethylbiphenyl (HMTPD), or mCP.

In an exemplary embodiment, the electron blocking material may include acompound represented by Formula 2, but the inventive concepts are notlimited thereto:

In Formula 2, X₁₁ may be selected from O, S, N(R₁₃), and C(R₁₃)(R₁₄),X₁₂ may be selected from a single bond, O, S, N(R₁₅), and C(R₁₅)(R₁₆),Al₁ and A₁₂ may each independently be selected from a C₅-C₆₀ carbocyclicgroup and a C₁-C₆₀ heterocyclic group, R₁₁ to R₁₆ may each independentlybe selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxylgroup, a cyano group, a nitro group, an amidino group, a hydrazinogroup, a hydrazono group, a substituted or unsubstituted C₁-C₆₀ alkylgroup, a substituted or unsubstituted C₂-C₆₀ alkenyl group, asubstituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted orunsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylgroup, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, asubstituted or unsubstituted C₆-C₆₀ aryl group, a substituted orunsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstitutedC₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroarylgroup, a substituted or unsubstituted C₁-C₆₀ heteroaryloxy group, asubstituted or unsubstituted C₁-C₆₀ heteroarylthio group, a substitutedor unsubstituted monovalent non-aromatic condensed polycyclic group, asubstituted or unsubstituted monovalent non-aromatic condensedheteropolycyclic group, —Si(Q₁)(Q₂)(Q₃), —B(Q₁)(Q₂), —N(Q₁)(Q₂),—P(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)(Q₁), —S(═O)₂(Q₁), —P(═O)(Q₁)(Q₂), and—P(═S)(Q₁)(Q₂), b11 and b12 may each independently be selected from 1,2, 3, 4, 5, and 6, and Q₁ to Q₃ may each independently be selected fromhydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group,a nitro group, an amidino group, a hydrazino group, a hydrazono group, aC₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, aC₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, aC₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a C₁-C₆₀ heteroaryloxygroup, a C₁-C₆₀ heteroarylthio group, a monovalent non-aromaticcondensed polycyclic group, a monovalent non-aromatic condensedheteropolycyclic group, a biphenyl group, and a terphenyl group.

In an exemplary embodiment, the electron blocking material may beselected from Compounds 1 to 12, but the inventive concepts are notlimited thereto:

The electron blocking layer 131 may consist of a single compound, andmay include a mixture of two or more different compounds.

In an exemplary embodiment, the electron blocking material may be thesame as the host, but the inventive concepts are not limited thereto.For example, the electron blocking material may be the same as the holetransport host, but the inventive concepts are not limited thereto.

In an exemplary embodiment, a thickness (D_(EB)) of the electronblocking layer 131 and a thickness (D_(E)) of the emission layer 150 maysatisfy D_(E)≥D_(EB). Specifically, the thickness (D_(EB)) of theelectron blocking layer 131 and the thickness (D_(E)) of the emissionlayer 150 may satisfy D_(E)>D_(EB), but the inventive concepts are notlimited thereto. When the thickness (D_(EB)) of the electron blockinglayer 131 and the thickness (D_(E)) of the emission layer 150 satisfythese ranges, it is possible to obtain a desired efficiency improvementeffect without increasing the driving voltage of the organiclight-emitting device.

In an exemplary embodiment, the thickness of the electron blocking layer131 may be in a range of about 10 Å to about 200 Å, but embodiments ofthe present disclosure are not limited thereto. When thickness of theelectron blocking layer 131 is within this range, it is possible toobtain a desired efficiency improvement effect without substantiallyincreasing the driving voltage of the organic light-emitting device.

[Emission Layer 150]

When the organic light-emitting device 10 is a full-color organiclight-emitting device, the emission layer 150 may be patterned into ared emission layer, a green emission layer, or a blue emission layer,according to a sub-pixel. In one or more embodiments, the emission layer150 may have a stacked structure of two or more layers selected from ared emission layer, a green emission layer, and a blue emission layer,in which the two or more layers contact each other or are separated fromeach other. In one or more embodiments, the emission layer may includetwo or more materials selected from a red light-emitting material, agreen light-emitting material, and a blue light-emitting material, inwhich the two or more materials are mixed with each other in a singlelayer to emit white light.

The emission layer 150 may include a host and a dopant. The dopant mayinclude a fluorescent dopant. For example, the dopant may include adelayed fluorescent dopant.

In the emission layer 150, an amount of the dopant may be in a range ofabout 0.01 parts by weight to about 15 parts by weight based on 100parts by weight of the host, but the inventive concepts are not limitedthereto.

A thickness of the emission layer 150 may be in a range of about 100 Åto about 1,000 Å, for example, about 200 Å to about 600 Å. When thethickness of the emission layer 150 is within this range, excellentlight-emission characteristics may be obtained without a substantialincrease in driving voltage.

[Host in Emission Layer 150]

In an exemplary embodiment, the host may include a compound representedby Formula 301 below:

[Ar₃₀₁]_(xb11)-[(L₃₀₁)_(xb1)-R₃₀₁]_(xb21)  Formula 301

In Formula 301, Ar₃₀₁ may be a substituted or unsubstituted C₅-C₆₀carbocyclic group or a substituted or unsubstituted C₁-C₆₀ heterocyclicgroup, xb11 may be 1, 2, or 3, L₃₀₁ may be selected from a substitutedor unsubstituted C₃-C₁₀ cycloalkylene group, a substituted orunsubstituted C₁-C₁₀ heterocycloalkylene group, a substituted orunsubstituted C₃-C₁₀ cycloalkenylene group, a substituted orunsubstituted C₁-C₁₀ heterocycloalkenylene group, a substituted orunsubstituted C₆-C₆₀ arylene group, a substituted or unsubstitutedC₁-C₆₀ heteroarylene group, a substituted or unsubstituted divalentnon-aromatic condensed polycyclic group, and a substituted orunsubstituted divalent non-aromatic condensed heteropolycyclic group,xb1 may be an integer from 0 to 5, R₃₀₁ may be selected from deuterium,—F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, anamidino group, a hydrazino group, a hydrazono group, a substituted orunsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, asubstituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted orunsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstitutedC₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ arylgroup, a substituted or unsubstituted C₆-C₆₀ aryloxy group, asubstituted or unsubstituted C₆-C₆₀ arylthio group, a substituted orunsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstitutedmonovalent non-aromatic condensed polycyclic group, a substituted orunsubstituted monovalent non-aromatic condensed heteropolycyclic group,—Si(Q₃₀₁)(Q₃₀₂)(Q₃₀₃), —N(Q₃₀₁)(Q₃₀₂), —B(Q₃₀₁)(Q₃₀₂), —C(═O)(Q₃₀₁),—S(═O)₂(Q₃₀₁), and —P(═O)(Q₃₀₁)(Q₃₀₂), xb21 may be an integer from 1 to5, and Q₃₀₁ to Q₃₀₃ may each independently be selected from a C₁-C₁₀alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, and a naphthyl group, but the inventive concepts arenot limited thereto.

In an exemplary embodiment, in Formula 301, Ar₃₀₁ may be selected from:a naphthalene group, a fluorene group, a spiro-bifluorene group, abenzofluorene group, a dibenzofluorene group, a phenalene group, aphenanthrene group, an anthracene group, a fluoranthene group, atriphenylene group, a pyrene group, a chrysene group, a naphthacenegroup, a picene group, a perylene group, a pentaphene group, anindenoanthracene group, a dibenzofuran group, and a dibenzothiophenegroup; and a naphthalene group, a fluorene group, a spiro-bifluorenegroup, a benzofluorene group, a dibenzofluorene group, a phenalenegroup, a phenanthrene group, an anthracene group, a fluoranthene group,a triphenylene group, a pyrene group, a chrysene group, a naphthacenegroup, a picene group, a perylene group, a pentaphene group, anindenoanthracene group, a dibenzofuran group, and a dibenzothiophenegroup, each substituted with at least one selected from deuterium, —F,—Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidinogroup, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, aC₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenylgroup, a naphthyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂),—C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), and Q₃₁ to Q₃₃ may eachindependently be selected from a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxygroup, a phenyl group, a biphenyl group, a terphenyl group, and anaphthyl group, but the inventive concepts are not limited thereto.

In Formula 301, when xb11 is two or more, two or more Ar₃₀₁(s) may belinked via a single bond.

In one or more exemplary embodiments, the compound represented byFormula 301 may be represented by Formula 301-1 or 301-2:

In Formulae 301-1 and 301-2, A₃₀₁ to A₃₀₄ may each independently beselected from a benzene group, a naphthalene group, a phenanthrenegroup, a fluoranthene group, a triphenylene group, a pyrene group, achrysene group, a pyridine group, a pyrimidine group, an indene group, afluorene group, a spiro-bifluorene group, a benzofluorene group, adibenzofluorene group, an indole group, a carbazole group, abenzocarbazole group, a dibenzocarbazole group, a furan group, abenzofuran group, a dibenzofuran group, a naphthofuran group, abenzonaphthofuran group, a dinaphthofuran group, a thiophene group, abenzothiophene group, a dibenzothiophene group, a naphthothiophenegroup, a benzonaphthothiophene group, and a dinaphthothiophene group,X₃₀₁ may be O, S, or N-[(L₃₀₄)_(xb4)-R₃₀₄], R₃₁₁ to R₃₁₄ may eachindependently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, ahydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, anaphthyl group —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂),—C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), xb22 and xb23 may eachindependently be 0, 1, or 2, L₃₀₁, xb1, R₃₀₁, and Q₃₁ to Q₃₃ are thesame as described above, L₃₀₂ to L₃₀₄ may each independently be the sameas defined in connection with L₃₀₁, xb2 to xb4 may each independently bethe same as defined in connection with xb1, and R₃₀₂ to R₃₀₄ may eachindependently be the same as defined in connection with R₃₀₁.

For example, in Formulae 301, 301-1, and 301-2, L₃₀₁ to L₃₀₄ may eachindependently be selected from: a phenylene group, a naphthylene group,a fluorenylene group, a spiro-bifluorenylene group, a benzofluorenylenegroup, a dibenzofluorenylene group, a phenanthrenylene group, ananthracenylene group, a fluoranthenylene group, a triphenylenylenegroup, a pyrenylene group, a chrysenylene group, a perylenylene group, apentaphenylene group, a hexacenylene group, a pentacenylene group, athiophenylene group, a furanylene group, a carbazolylene group, anindolylene group, an isoindolylene group, a benzofuranylene group, abenzothiophenylene group, a dibenzofuranylene group, adibenzothiophenylene group, a benzocarbazolylene group, adibenzocarbazolylene group, a dibenzosilolylene group, a pyridinylenegroup, an imidazolylene group, a pyrazolylene group, a thiazolylenegroup, an isothiazolylene group, an oxazolylene group, an isoxazolylenegroup, a thiadiazolylene group, an oxadiazolylene group, a pyrazinylenegroup, a pyrimidinylene group, a pyridazinylene group, a triazinylenegroup, a quinolinylene group, an isoquinolinylene group, abenzoquinolinylene group, a phthalazinylene group, a naphthyridinylenegroup, a quinoxalinylene group, a quinazolinylene group, a cinnolinylenegroup, a phenanthridinylene group, an acridinylene group, aphenanthrolinylene group, a phenazinylene group, a benzimidazolylenegroup, an isobenzothiazolylene group, a benzoxazolylene group, anisobenzoxazolylene group, a triazolylene group, a tetrazolylene group,an imidazopyridinylene group, an imidazopyrimidinylene group, and anazacarbazolylene group; and a phenylene group, a naphthylene group, afluorenylene group, a spiro-bifluorenylene group, a benzofluorenylenegroup, a dibenzofluorenylene group, a phenanthrenylene group, ananthracenylene group, a fluoranthenylene group, a triphenylenylenegroup, a pyrenylene group, a chrysenylene group, a perylenylene group, apentaphenylene group, a hexacenylene group, a pentacenylene group, athiophenylene group, a furanylene group, a carbazolylene group, anindolylene group, an isoindolylene group, a benzofuranylene group, abenzothiophenylene group, a dibenzofuranylene group, adibenzothiophenylene group, a benzocarbazolylene group, adibenzocarbazolylene group, a dibenzosilolylene group, a pyridinylenegroup, an imidazolylene group, a pyrazolylene group, a thiazolylenegroup, an isothiazolylene group, an oxazolylene group, an isoxazolylenegroup, a thiadiazolylene group, an oxadiazolylene group, a pyrazinylenegroup, a pyrimidinylene group, a pyridazinylene group, a triazinylenegroup, a quinolinylene group, an isoquinolinylene group, abenzoquinolinylene group, a phthalazinylene group, a naphthyridinylenegroup, a quinoxalinylene group, a quinazolinylene group, a cinnolinylenegroup, a phenanthridinylene group, an acridinylene group, aphenanthrolinylene group, a phenazinylene group, a benzimidazolylenegroup, an isobenzothiazolylene group, a benzoxazolylene group, anisobenzoxazolylene group, a triazolylene group, a tetrazolylene group,an imidazopyridinylene group, an imidazopyrimidinylene group, and anazacarbazolylene group, each substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, a naphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenylgroup, a phenanthrenyl group, an anthracenyl group, a fluoranthenylgroup, a triphenylenyl group, a pyrenyl group, a chrysenyl group, aperylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a thiophenyl group, a furanyl group, a carbazolyl group, anindolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a pyridinyl group, an imidazolyl group, apyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group,a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinylgroup, a quinolinyl group, an isoquinolinyl group, a benzoquinolinylgroup, a phthalazinyl group, a naphthyridinyl group, a quinoxalinylgroup, a quinazolinyl group, a cinnolinyl group, a phenanthridinylgroup, an acridinyl group, a phenanthrolinyl group, a phenazinyl group,a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolylgroup, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group,an imidazopyridinyl group, an imidazopyrimidinyl group, an azacarbazolylgroup, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁),—S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), and Q₃₁ to Q₃₃ are the same asdescribed above.

In an exemplary embodiment, in Formulae 301, 301-1, and 301-2, R₃₀₁ toR₃₀₄ may each independently be selected from: a phenyl group, a biphenylgroup, a terphenyl group, a naphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenylgroup, a phenanthrenyl group, an anthracenyl group, a fluoranthenylgroup, a triphenylenyl group, a pyrenyl group, a chrysenyl group, aperylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a thiophenyl group, a furanyl group, a carbazolyl group, anindolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a pyridinyl group, an imidazolyl group, apyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group,a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinylgroup, a quinolinyl group, an isoquinolinyl group, a benzoquinolinylgroup, a phthalazinyl group, a naphthyridinyl group, a quinoxalinylgroup, a quinazolinyl group, a cinnolinyl group, a phenanthridinylgroup, an acridinyl group, a phenanthrolinyl group, a phenazinyl group,a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolylgroup, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group,an imidazopyridinyl group, an imidazopyrimidinyl group, and anazacarbazolyl group; and a phenyl group, a biphenyl group, a terphenylgroup, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, abenzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group,an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, apyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenylgroup, a hexacenyl group, a pentacenyl group, a thiophenyl group, afuranyl group, a carbazolyl group, an indolyl group, an isoindolylgroup, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranylgroup, a dibenzothiophenyl group, a benzocarbazolyl group, adibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, animidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolylgroup, an oxazolyl group, an isoxazolyl group, a thiadiazolyl group, anoxadiazolyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinylgroup, a triazinyl group, a quinolinyl group, an isoquinolinyl group, abenzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, aquinoxalinyl group, a quinazolinyl group, a cinnolinyl group, aphenanthridinyl group, an acridinyl group, a phenanthrolinyl group, aphenazinyl group, a benzimidazolyl group, an isobenzothiazolyl group, abenzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, atetrazolyl group, an imidazopyridinyl group, an imidazopyrimidinylgroup, and an azacarbazolyl group, each substituted with at least oneselected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyanogroup, a nitro group, an amidino group, a hydrazino group, a hydrazonogroup, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, abiphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group,a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenylgroup, a phenanthrenyl group, an anthracenyl group, a fluoranthenylgroup, a triphenylenyl group, a pyrenyl group, a chrysenyl group, aperylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a thiophenyl group, a furanyl group, a carbazolyl group, anindolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a pyridinyl group, an imidazolyl group, apyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group,a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinylgroup, a quinolinyl group, an isoquinolinyl group, a benzoquinolinylgroup, a phthalazinyl group, a naphthyridinyl group, a quinoxalinylgroup, a quinazolinyl group, a cinnolinyl group, a phenanthridinylgroup, an acridinyl group, a phenanthrolinyl group, a phenazinyl group,a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolylgroup, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group,an imidazopyridinyl group, an imidazopyrimidinyl group, an azacarbazolylgroup, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁),—S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), and Q₃₁ and Q₃₃ are the same asdescribed above.

In one or more exemplary embodiments, the host may include an alkalineearth metal complex. For example, the host may be selected from a Becomplex (for example, Compound H55), a Mg complex, and a Zn complex.

The host may include at least one selected from9,10-di(2-naphthyl)anthracene (ADN),2-methyl-9,10-bis(naphthalen-2-yl)anthracene (MADN),9,10-di-(2-naphthyl)-2-t-butyl-anthracene (TBADN),4,4′-bis(N-carbazolyl)-1,1′-biphenyl (CBP), 1,3-di-9-carbazolylbenzene(mCP), 1,3,5-tri(carbazol-9-yl)benzene (TCP), and Compounds H1 to H60,but the inventive concepts are not limited thereto:

In an exemplary embodiment, the host may include at least one selectedfrom a silicon-containing compound (for example, BCPDS used in thefollowing examples or the like) and a phosphine oxide-containingcompound (for example, POPCPA used in the following examples or thelike).

However, the inventive concepts are not limited thereto. In an exemplaryembodiment, the host may include only one compound, or two or moredifferent compounds (for example, a host used in the following examplesincludes BCPDS and POPCPA).

[Fluorescent Dopant in Emission Layer 150]

The fluorescent dopant may include an organometallic complex representedby Formula 2 or 3.

The dopant may emit thermally activated delayed fluorescence orfluorescence.

Specifically, the dopant may further satisfy Equation 2:

|S ₁(D)−T ₁(D)|≤0.5 eV.  Equation 2

In Equation 2, T₁(D) is a lowest excitation triplet energy level of thedopant, and S₁(D) is a lowest excitation singlet energy level of thedopant.

When the dopant satisfies Equation 2, the dopant may emit thermallyactivated delayed fluorescence even at room temperature.

More specifically, the dopant may satisfy |S₁(D)−T₁(D)|≤0.2 eV, but theinventive concepts are not limited thereto.

In an exemplary embodiment, the dopant may further satisfy Equation 3and/or Equation 4, but the inventive concepts are not limited thereto:

2.65 eV≤S ₁(D)≤2.85 eV  Equation 3

2.65 eV≤T ₁(D)≤3.05 eV.  Equation 4

In Equations 3 and 4, T₁(D) is a lowest excitation triplet energy levelof the dopant, and S₁(D) is a lowest excitation singlet energy level ofthe dopant.

When the dopant satisfies Equation 3 and/or Equation 4, the dopant mayemit blue light.

In one or more exemplary embodiments, the dopant may not include a metalatom. That is, the dopant is clearly different from a phosphorescenceemitter including a metal atom.

For example, the dopant may have a D-type structure including anelectron donating group (D) and an electron accepting group (A).Specifically, the dopant may be compounds disclosed in Japanese PatentApplication Laid-Open Nos. 2011-140046, 2013-034967, 2015-530745,2013-034967, 2014-512416, 2015-525248, 2013-524707, 2013-547225,2012-274324, and 2015-504322, U.S. Patent Application Publication No.2012-0217869, International Publication Nos. 2015-118035, 2016-091887,and 2016-096851, Korean Patent Application Publication No.10-2017-7005332, Japanese Patent Application Laid-Open No. 2014-518737,U.S. Patent Application Publication Nos. 2016-0197286, 2014-0138627,2014-0145149, 2014-0158992, 2014-0145151, 2015-0021555, and2014-0332758, Korean Patent Application Publication No. 2014-0154391,Japanese Patent Application Laid-Open Nos. 2015-148588, 2016-506442,2015-531748, 2016-538300, 2016-538393, 2015-095814, 2012-538639,2014-525803, 2012-546858, 2016-538300, and 2014-538540, but theinventive concepts are not limited thereto.

In an exemplary embodiment, the dopant may have a D-A-D-type or A-D-typestructure. Specifically the dopant may be compounds disclosed inInternational Publication No. 2015-158692 and Japanese PatentApplication Laid-Open Nos. 2016-538435, 2016-538426, 2015-500308, and2015-527231, but the inventive concepts are not limited thereto.

For example, the dopant may be 4CZIPN, but the inventive concepts arenot limited thereto:

In an exemplary embodiment, the dopant may be a transition metalcomplex. Specifically, the dopant may be a Cu complex or a Pt complex,and may be compounds disclosed in Korean Patent Application PublicationNos. 10-2012-7017497, 10-2013-7001396, 10-2014-0068027, and10-2014-7003327 and U.S. Patent Application Publication No.2011-0304262, but the inventive concepts are not limited thereto.

In an exemplary embodiment, the dopant may be a compound including a B—Nstructure, and may be a compound disclosed in U.S. Patent ApplicationPublication No. 2014-0027734, but the inventive concepts are not limitedthereto.

For example, the dopant may be DABNA-1 or DABNA-2, but ethe inventiveconcepts are not limited thereto:

In an exemplary embodiment, the dopant may be compounds disclosed inJapanese Patent Application Laid-Open Nos. 2015-508569 and 2014-554306,but the inventive concepts are not limited thereto.

The electron donating group (D) may be, for example, a carbazole group,a dibenzothiophene group, a dibenzofuran group, an indolocarbazolegroup, and a bis-carbazole group, but the inventive concepts are notlimited thereto.

The electron accepting group (A) may be CN, F, an aryl group substitutedby CN and/or F, or a π electron-depleted nitrogen-containing cyclicgroup, but the inventive concepts are not limited thereto.

In addition, the fluorescent dopant may further include an arylaminecompound or a styrylamine compound.

The fluorescent dopant may include a compound represented by Formula 501below:

In Formula 501, Ar₅₀₁ may be a substituted or unsubstituted C₅-C₆₀carbocyclic group or a substituted or unsubstituted C₁-C₆₀ heterocyclicgroup, L₅₀₁ to L₅₀₃ may each independently be selected from asubstituted or unsubstituted C₃-C₁₀ cycloalkylene group, a substitutedor unsubstituted C₁-C₁₀ heterocycloalkylene group, a substituted orunsubstituted C₃-C₁₀ cycloalkenylene group, a substituted orunsubstituted C₁-C₁₀ heterocycloalkenylene group, a substituted orunsubstituted C₆-C₆₀ arylene group, a substituted or unsubstitutedC₁-C₆₀ heteroarylene group, a substituted or unsubstituted divalentnon-aromatic condensed polycyclic group, and a substituted orunsubstituted divalent non-aromatic condensed heteropolycyclic group,xd1 to xd3 may each independently be an integer from 0 to 3, R₅₀₁ andR₅₀₂ may each independently be selected from a substituted orunsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstitutedC₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ arylgroup, a substituted or unsubstituted C₆-C₆₀ aryloxy group, asubstituted or unsubstituted C₆-C₆₀ arylthio group, a substituted orunsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstitutedmonovalent non-aromatic condensed polycyclic group, and a substituted orunsubstituted monovalent non-aromatic condensed heteropolycyclic group,and xd4 may be an integer from 1 to 6.

In an exemplary embodiment, Ar₅₀₁ in Formula 501 may be selected from: anaphthalene group, a heptalene group, a fluorene group, aspiro-bifluorene group, a benzofluorene group, a dibenzofluorene group,a phenalene group, a phenanthrene group, an anthracene group, afluoranthene group, a triphenylene group, a pyrene group, a chrysenegroup, a naphthacene group, a picene group, a perylene group, apentaphene group, an indenoanthracene group, and an indenophenanthrenegroup; and a naphthalene group, a heptalene group, a fluorene group, aspiro-bifluorene group, a benzofluorene group, a dibenzofluorene group,a phenalene group, a phenanthrene group, an anthracene group, afluoranthene group, a triphenylene group, a pyrene group, a chrysenegroup, a naphthacene group, a picene group, a perylene group, apentaphene group, an indenoanthracene group, and an indenophenanthrenegroup, each substituted with at least one selected from deuterium, —F,—Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidinogroup, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, aC₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenylgroup, and a naphthyl group.

In one or more exemplary embodiments, in Formula 501, L₅₀₁ to L₅₀₃ mayeach independently be selected from: a phenylene group, a naphthylenegroup, a fluorenylene group, a spiro-bifluorenylene group, abenzofluorenylene group, a dibenzofluorenylene group, a phenanthrenylenegroup, an anthracenylene group, a fluoranthenylene group, atriphenylenylene group, a pyrenylene group, a chrysenylene group, aperylenylene group, a pentaphenylene group, a hexacenylene group, apentacenylene group, a thiophenylene group, a furanylene group, acarbazolylene group, an indolylene group, an isoindolylene group, abenzofuranylene group, a benzothiophenylene group, a dibenzofuranylenegroup, a dibenzothiophenylene group, a benzocarbazolylene group, adibenzocarbazolylene group, a dibenzosilolylene group, and apyridinylene group; and a phenylene group, a naphthylene group, afluorenylene group, a spiro-bifluorenylene group, a benzofluorenylenegroup, a dibenzofluorenylene group, a phenanthrenylene group, ananthracenylene group, a fluoranthenylene group, a triphenylenylenegroup, a pyrenylene group, a chrysenylene group, a perylenylene group, apentaphenylene group, a hexacenylene group, a pentacenylene group, athiophenylene group, a furanylene group, a carbazolylene group, anindolylene group, an isoindolylene group, a benzofuranylene group, abenzothiophenylene group, a dibenzofuranylene group, adibenzothiophenylene group, a benzocarbazolylene group, adibenzocarbazolylene group, a dibenzosilolylene group, a pyridinylenegroup, each substituted with at least one selected from deuterium, —F,—Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidinogroup, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, aC₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenylgroup, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, abenzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group,an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, apyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenylgroup, a hexacenyl group, a pentacenyl group, a thiophenyl group, afuranyl group, a carbazolyl group, an indolyl group, an isoindolylgroup, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranylgroup, a dibenzothiophenyl group, a benzocarbazolyl group, adibenzocarbazolyl group, a dibenzosilolyl group, and a pyridinyl group.

In one or more exemplary embodiments, in Formula 501, R₅₀₁ and R₅₀₂ mayeach independently be selected from: a phenyl group, a biphenyl group, aterphenyl group, a naphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenylgroup, a phenanthrenyl group, an anthracenyl group, a fluoranthenylgroup, a triphenylenyl group, a pyrenyl group, a chrysenyl group, aperylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a thiophenyl group, a furanyl group, a carbazolyl group, anindolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, and a pyridinyl group; and a phenyl group, abiphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group,a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenylgroup, a phenanthrenyl group, an anthracenyl group, a fluoranthenylgroup, a triphenylenyl group, a pyrenyl group, a chrysenyl group, aperylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a thiophenyl group, a furanyl group, a carbazolyl group, anindolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, and a pyridinyl group, each substituted with atleast one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, acyano group, a nitro group, an amidino group, a hydrazino group, ahydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenylgroup, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenylgroup, a perylenyl group, a pentaphenyl group, a hexacenyl group, apentacenyl group, a thiophenyl group, a furanyl group, a carbazolylgroup, an indolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a pyridinyl group, and —Si(Q₃₁)(Q₃₂)(Q₃₃), and Q₃₁to Q₃₃ may each independently be selected from a C₁-C₁₀ alkyl group, aC₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, a terphenylgroup, and a naphthyl group.

In one or more exemplary embodiments, in Formula 501, xd4 may be 2, butthe inventive concepts are not limited thereto.

For example, the fluorescent dopant may be selected from Compounds FD1to FD22:

In an exemplary embodiment, the fluorescent dopant may be selected fromthe following compounds, but the inventive concepts are not limitedthereto.

[Electron Transport Region in Organic Layer]

The electron transport region may have i) a single-layered structureincluding a single layer including a single material, ii) asingle-layered structure including a single layer including a pluralityof different materials, or iii) a multi-layered structure having aplurality of layers including a plurality of different materials.

The electron transport region may include at least one selected from abuffer layer, a hole blocking layer 132, an electron control layer, anelectron transport layer, and an electron injection layer, but theinventive concepts are not limited thereto.

For example, the electron transport region may have an electrontransport layer/electron injection layer structure, an electrontransport layer/electron injection layer structure, an electron controllayer/electron transport layer/electron injection layer structure, abuffer layer/electron transport layer/electron injection layerstructure, a hole blocking layer 132/electron transport layer/electroninjection layer structure, a hole blocking layer 132/electron controllayer/electron transport layer/electron injection layer structure, or ahole blocking layer 132/buffer layer/electron transport layer/electroninjection layer, wherein for each structure, constituting layers aresequentially stacked from the emission layer 150, but the structure ofthe hole transport region is not limited thereto.

The hole blocking material included in the hole blocking layer 132 maysatisfy 2.5 eV≤T₁(BL)≤3.5 eV, but the inventive concepts are not limitedthereto. When the hole blocking material satisfies this range, excitonsare substantially trapped in the emission layer, and excitons of theemission layer may sufficiently participate in light emission.

The hole blocking material may be represented by Formula 3, but theinventive concepts are not limited thereto:

In Formula 3, X₂₁ may be N or C(R₂₁), X₂₂ may be N or C(R₂₂), X₂₃ may beN or C(R₂₃), X₂₄ may be N or C(R₂₄), X₂₅ may be N or C(R₂₅), and X₂₆ maybe N or C(R₂₆), wherein at least one selected from X₂₁ to X₂₆ may be N,

R₂₁ to R₂₆ may each independently be selected from hydrogen, deuterium,a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted orunsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstitutedmonovalent non-aromatic condensed polycyclic group, and a substituted orunsubstituted monovalent non-aromatic condensed heteropolycyclic group,and at least one selected from R₂₁ to R₂₆ may be selected from asubstituted or unsubstituted C₆-C₆₀ aryl group, a substituted orunsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstitutedmonovalent non-aromatic condensed polycyclic group, and a substituted orunsubstituted monovalent non-aromatic condensed heteropolycyclic group.

In an exemplary embodiment, the hole blocking material may be selectedfrom Compounds 21 to 28, but the inventive concepts are not limitedthereto:

The hole blocking layer 132 may consist of a single compound, or mayinclude a mixture of two or more different compounds.

In an exemplary embodiment, the hole blocking material may be the sameas the host, but the inventive concepts not limited thereto. Forexample, the hole blocking material may be the same as the electrontransport host, but the inventive concepts are not limited thereto.

In an exemplary embodiment, a thickness (D_(HB)) of the hole blockinglayer 132 and a thickness (D_(E)) Of the emission layer 150 may satisfyD_(E)≥D_(HB). Specifically, the thickness (D_(HB)) Of the hole blockinglayer 132 and the thickness (D_(E)) Of the emission layer 150 maysatisfy D_(E)>D_(HB), but the inventive concepts are not limitedthereto. When the thickness (D_(HB)) Of the hole blocking layer 132 andthe thickness (D_(E)) Of the emission layer 150 satisfy these ranges, itis possible to obtain a desired efficiency improvement effect withoutincreasing the driving voltage of the organic light-emitting device.

In one or more exemplary embodiments, the thickness of the hole blockinglayer 132 may be in a range of about 10 Å to about 200 Å, butembodiments of the present disclosure are not limited thereto. Whenthickness of the hole blocking layer 132 is within this range, it ispossible to obtain a desired efficiency improvement effect withoutsubstantially increasing the driving voltage of the organiclight-emitting device.

The electron transport region (for example, a buffer layer, a holeblocking layer, an electron control layer, or an electron transportlayer in the electron transport region) may include a metal-freecompound containing at least one π electron-depleted nitrogen-containingring.

The “π electron-depleted nitrogen-containing ring” indicates a C₁-C₆₀heterocyclic group having at least one *—N=*′ moiety as a ring-formingmoiety.

For example, the “π electron-depleted nitrogen-containing ring” may bei) a 5-membered to 7-membered heteromonocyclic group having at least one*—N=*′ moiety, ii) a heteropolycyclic group in which two or more5-membered to 7-membered heteromonocyclic groups each having at leastone *—N=*′ moiety are condensed with each other, or iii) aheteropolycyclic group in which at least one of 5-membered to 7-memberedheteromonocyclic groups, each having at least one *—N=*′ moiety, iscondensed with at least one C₅-C₆₀ carbocyclic group.

Examples of the π electron-depleted nitrogen-containing ring include animidazole, a pyrazole, a thiazole, an isothiazole, an oxazole, anisoxazole, a pyridine, a pyrazine, a pyrimidine, a pyridazine, anindazole, a purine, a quinoline, an isoquinoline, a benzoquinoline, aphthalazine, a naphthyridine, a quinoxaline, a quinazoline, a cinnoline,a phenanthridine, an acridine, a phenanthroline, a phenazine, abenzimidazole, an isobenzothiazole, a benzoxazole, an isobenzoxazole, atriazole, a tetrazole, an oxadiazole, a triazine, thiadiazole, animidazopyridine, an imidazopyrimidine, and an azacarbazole, but are notlimited thereto.

For example, the electron transport region may include a compoundrepresented by Formula 601:

[Ar₆₀₁]_(xe11)-[(L₆₀₁)_(xe1)-R₆₀₁]_(xe21)  Formula 601

In Formula 601, Ar₆₀₁ may be a substituted or unsubstituted C₅-C₆₀carbocyclic group or a substituted or unsubstituted C₁-C₆₀ heterocyclicgroup, xe11 may be 1, 2, or 3, L₆₀₁ may be selected from a substitutedor unsubstituted C₃-C₁₀ cycloalkylene group, a substituted orunsubstituted C₁-C₁₀ heterocycloalkylene group, a substituted orunsubstituted C₃-C₁₀ cycloalkenylene group, a substituted orunsubstituted C₁-C₁₀ heterocycloalkenylene group, a substituted orunsubstituted C₆-C₆₀ arylene group, a substituted or unsubstitutedC₁-C₆₀ heteroarylene group, a substituted or unsubstituted divalentnon-aromatic condensed polycyclic group, and a substituted orunsubstituted divalent non-aromatic condensed heteropolycyclic group,xe1 may be an integer from 0 to 5, R₆₀₁ may be selected from asubstituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted orunsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted orunsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstitutedC₁-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, asubstituted or unsubstituted C₆-C₆₀ arylthio group, a substituted orunsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstitutedmonovalent non-aromatic condensed polycyclic group, a substituted orunsubstituted monovalent non-aromatic condensed heteropolycyclic group,—Si(Q₆₀₁)(Q₆₀₂)(Q₆₀₃), —C(═O)(Q₆₀₁), —S(═O)₂(Q₆₀₁), and—P(═O)(Q₆₀₁)(Q₆₀₂), and Q₆₀₁ to Q₆₀₃ may each independently be a C₁-C₁₀alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, or a naphthyl group, and xe21 may be an integer from 1to 5.

In an exemplary embodiment, at least one of Ar₆₀₁(s) in the number ofxe11 and R₆₀₁(s) in the number of xe21 may include the nelectron-depleted nitrogen-containing ring.

In an exemplary embodiment, ring Ar₆₀₁ in Formula 601 may be selectedfrom: a benzene group, a naphthalene group, a fluorene group, aspiro-bifluorene group, a benzofluorene group, a dibenzofluorene group,a phenalene group, a phenanthrene group, an anthracene group, afluoranthene group, a triphenylene group, a pyrene group, a chrysenegroup, a naphthacene group, a picene group, a perylene group, apentaphene group, an indenoanthracene group, a dibenzofuran group, adibenzothiophene group, a carbazole group, an imidazole group, apyrazole group, a thiazole group, an isothiazole group, an oxazolegroup, an isoxazole group, a pyridine group, a pyrazine group, apyrimidine group, a pyridazine group, an indazole group, a purine group,a quinoline group, an isoquinoline group, a benzoquinoline group, aphthalazine group, a naphthyridine group, a quinoxaline group, aquinazoline group, a cinnoline group, a phenanthridine group, anacridine group, a phenanthroline group, a phenazine group, abenzimidazole group, an isobenzothiazole group, a benzoxazole group, anisobenzoxazole group, a triazole group, a tetrazole group, an oxadiazolegroup, a triazine group, a thiadiazole group, an imidazopyridine group,an imidazopyrimidine group, and an azacarbazole group; and a benzenegroup, a naphthalene group, a fluorene group, a spiro-bifluorene group,a benzofluorene group, a dibenzofluorene group, a phenalene group, aphenanthrene group, an anthracene group, a fluoranthene group, atriphenylene group, a pyrene group, a chrysene group, a naphthacenegroup, a picene group, a perylene group, a pentaphene group, anindenoanthracene group, a dibenzofuran group, a dibenzothiophene group,a carbazole group, an imidazole group, a pyrazole group, a thiazolegroup, an isothiazole group, an oxazole group, an isoxazole group, apyridine group, a pyrazine group, a pyrimidine group, a pyridazinegroup, an indazole group, a purine group, a quinoline group, anisoquinoline group, a benzoquinoline group, a phthalazine group, anaphthyridine group, a quinoxaline group, a quinazoline group, acinnoline group, a phenanthridine group, an acridine group, aphenanthroline group, a phenazine group, a benzimidazole group, anisobenzothiazole group, a benzoxazole group, an isobenzoxazole group, atriazole group, a tetrazole group, an oxadiazole group, a triazinegroup, a thiadiazole group, an imidazopyridine group, animidazopyrimidine group, and an azacarbazole group, each substitutedwith at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxylgroup, a cyano group, a nitro group, an amidino group, a hydrazinogroup, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, aphenyl group, a biphenyl group, a terphenyl group, a naphthyl group,—Si(Q₃₁)(Q₃₂)(Q₃₃), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), and Q₃₁ to Q₃₃may each independently be selected from a C₁-C₁₀ alkyl group, a C₁-C₁₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, and anaphthyl group.

In Formula 601, when xe11 is two or more, two or more Ar₆₀₁(s) may belinked via a single bond.

In one or more exemplary embodiments, in Formula 601, Ar₆₀₁ may be ananthracene group.

In one or more exemplary embodiments, the compound represented byFormula 601 may be represented by Formula 601-1:

In Formula 601-1, X₆₁₄ may be N or C(R₆₁₄), X₆₁₅ may be N or C(R₆₁₅),and X₆₁₆ may be N or C(R₆₁₆), wherein at least one selected from X₆₁₄ toX₆₁₆ may be N, L₆₁₁ to L₆₁₃ may each independently be the same asdefined in connection with L₆₀₁, xe611 to xe613 may each independentlybe the same as defined in connection with xe1, R₆₁₁ to R₆₁₃ may eachindependently be the same as defined in connection with R₆₀₁, and R₆₁₄to R₆₁₆ may each independently be selected from hydrogen, deuterium, —F,—Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidinogroup, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, aC₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenylgroup, and a naphthyl group.

In an exemplary embodiment, in Formulae 601 and 601-1, L₆₀₁ and L₆₁₁ toL₆₁₃ may each independently be selected from: a phenylene group, anaphthylene group, a fluorenylene group, a spiro-bifluorenylene group, abenzofluorenylene group, a dibenzofluorenylene group, a phenanthrenylenegroup, an anthracenylene group, a fluoranthenylene group, atriphenylenylene group, a pyrenylene group, a chrysenylene group, aperylenylene group, a pentaphenylene group, a hexacenylene group, apentacenylene group, a thiophenylene group, a furanylene group, acarbazolylene group, an indolylene group, an isoindolylene group, abenzofuranylene group, a benzothiophenylene group, a dibenzofuranylenegroup, a dibenzothiophenylene group, a benzocarbazolylene group, adibenzocarbazolylene group, a dibenzosilolylene group, a pyridinylenegroup, an imidazolylene group, a pyrazolylene group, a thiazolylenegroup, an isothiazolylene group, an oxazolylene group, an isoxazolylenegroup, a thiadiazolylene group, an oxadiazolylene group, a pyrazinylenegroup, a pyrimidinylene group, a pyridazinylene group, a triazinylenegroup, a quinolinylene group, an isoquinolinylene group, abenzoquinolinylene group, a phthalazinylene group, a naphthyridinylenegroup, a quinoxalinylene group, a quinazolinylene group, a cinnolinylenegroup, a phenanthridinylene group, an acridinylene group, aphenanthrolinylene group, a phenazinylene group, a benzimidazolylenegroup, an isobenzothiazolylene group, a benzoxazolylene group, anisobenzoxazolylene group, a triazolylene group, a tetrazolylene group,an imidazopyridinylene group, an imidazopyrimidinylene group, and anazacarbazolylene group; and a phenylene group, a naphthylene group, afluorenylene group, a spiro-bifluorenylene group, a benzofluorenylenegroup, a dibenzofluorenylene group, a phenanthrenylene group, ananthracenylene group, a fluoranthenylene group, a triphenylenylenegroup, a pyrenylene group, a chrysenylene group, a perylenylene group, apentaphenylene group, a hexacenylene group, a pentacenylene group, athiophenylene group, a furanylene group, a carbazolylene group, anindolylene group, an isoindolylene group, a benzofuranylene group, abenzothiophenylene group, a dibenzofuranylene group, adibenzothiophenylene group, a benzocarbazolylene group, adibenzocarbazolylene group, a dibenzosilolylene group, a pyridinylenegroup, an imidazolylene group, a pyrazolylene group, a thiazolylenegroup, an isothiazolylene group, an oxazolylene group, an isoxazolylenegroup, a thiadiazolylene group, an oxadiazolylene group, a pyrazinylenegroup, a pyrimidinylene group, a pyridazinylene group, a triazinylenegroup, a quinolinylene group, an isoquinolinylene group, abenzoquinolinylene group, a phthalazinylene group, a naphthyridinylenegroup, a quinoxalinylene group, a quinazolinylene group, a cinnolinylenegroup, a phenanthridinylene group, an acridinylene group, aphenanthrolinylene group, a phenazinylene group, a benzimidazolylenegroup, an isobenzothiazolylene group, a benzoxazolylene group, anisobenzoxazolylene group, a triazolylene group, a tetrazolylene group,an imidazopyridinylene group, an imidazopyrimidinylene group, and anazacarbazolylene group, each substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, a naphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenylgroup, a phenanthrenyl group, an anthracenyl group, a fluoranthenylgroup, a triphenylenyl group, a pyrenyl group, a chrysenyl group, aperylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a thiophenyl group, a furanyl group, a carbazolyl group, anindolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a pyridinyl group, an imidazolyl group, apyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group,a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinylgroup, a quinolinyl group, an isoquinolinyl group, a benzoquinolinylgroup, a phthalazinyl group, a naphthyridinyl group, a quinoxalinylgroup, a quinazolinyl group, a cinnolinyl group, a phenanthridinylgroup, an acridinyl group, a phenanthrolinyl group, a phenazinyl group,a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolylgroup, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group,an imidazopyridinyl group, an imidazopyrimidinyl group, and anazacarbazolyl group, but the inventive concepts are not limited thereto.

In one or more exemplary embodiments, in Formulae 601 and 601-1, xe1 andxe611 to xe613 may each independently be 0, 1, or 2.

In one or more exemplary embodiments, in Formulae 601 and 601-1, R₆₀₁and R₆₁₁ to R₆₁₃ may each independently be selected from: a phenylgroup, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenylgroup, a perylenyl group, a pentaphenyl group, a hexacenyl group, apentacenyl group, a thiophenyl group, a furanyl group, a carbazolylgroup, an indolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a pyridinyl group, an imidazolyl group, apyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group,a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinylgroup, a quinolinyl group, an isoquinolinyl group, a benzoquinolinylgroup, a phthalazinyl group, a naphthyridinyl group, a quinoxalinylgroup, a quinazolinyl group, a cinnolinyl group, a phenanthridinylgroup, an acridinyl group, a phenanthrolinyl group, a phenazinyl group,a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolylgroup, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group,an imidazopyridinyl group, an imidazopyrimidinyl group, and anazacarbazolyl group; a phenyl group, a biphenyl group, a terphenylgroup, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, abenzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group,an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, apyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenylgroup, a hexacenyl group, a pentacenyl group, a thiophenyl group, afuranyl group, a carbazolyl group, an indolyl group, an isoindolylgroup, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranylgroup, a dibenzothiophenyl group, a benzocarbazolyl group, adibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, animidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolylgroup, an oxazolyl group, an isoxazolyl group, a thiadiazolyl group, anoxadiazolyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinylgroup, a triazinyl group, a quinolinyl group, an isoquinolinyl group, abenzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, aquinoxalinyl group, a quinazolinyl group, a cinnolinyl group, aphenanthridinyl group, an acridinyl group, a phenanthrolinyl group, aphenazinyl group, a benzimidazolyl group, an isobenzothiazolyl group, abenzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, atetrazolyl group, an imidazopyridinyl group, an imidazopyrimidinylgroup, and an azacarbazolyl group, each substituted with at least oneselected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyanogroup, a nitro group, an amidino group, a hydrazino group, a hydrazonogroup, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, abiphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group,a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenylgroup, a phenanthrenyl group, an anthracenyl group, a fluoranthenylgroup, a triphenylenyl group, a pyrenyl group, a chrysenyl group, aperylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a thiophenyl group, a furanyl group, a carbazolyl group, anindolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a pyridinyl group, an imidazolyl group, apyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group,a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinylgroup, a quinolinyl group, an isoquinolinyl group, a benzoquinolinylgroup, a phthalazinyl group, a naphthyridinyl group, a quinoxalinylgroup, a quinazolinyl group, a cinnolinyl group, a phenanthridinylgroup, an acridinyl group, a phenanthrolinyl group, a phenazinyl group,a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolylgroup, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group,an imidazopyridinyl group, an imidazopyrimidinyl group, and anazacarbazolyl group; and —S(═O)₂(Q₆₀₁) and —P(═O)(Q₆₀₁)(Q₆₀₂), and Q₆₀₁and Q₆₀₂ are the same as described above.

The electron transport region may include at least one compound selectedfrom Compounds ET1 to ET36, but the inventive concepts are not limitedthereto:

In one or more exemplary embodiments, the electron transport region mayinclude at least one selected from2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP),4,7-dphenyl-1,10-phenanthroline (Bphen), Alq3, BAlq,3-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole(TAZ), and NTAZ:

In an exemplary embodiment, the electron transport region may include aphosphine oxide-containing compound (for example, TSPO1 used in thefollowing examples or the like), but embodiments of the presentdisclosure are not limited thereto. In one embodiment, the phosphineoxide-containing compound may be used in a hole blocking layer in theelectron transport region, but the inventive concepts are not limitedthereto.

Thicknesses of the buffer layer, the hole blocking layer, and theelectron control layer may each be in a range of about 20 Å to about1,000 Å, for example, about 30 Å to about 300 Å. When the thicknesses ofthe buffer layer, the hole blocking layer, and the electron controllayer are within these ranges, the electron blocking layer may haveexcellent electron blocking characteristics or electron controlcharacteristics without a substantial increase in driving voltage.

A thickness of the electron transport layer may be in a range of about100 Å to about 1,000 Å, for example, about 150 Å to about 500 Å. Whenthe thickness of the electron transport layer is within the rangedescribed above, the electron transport layer may have satisfactoryelectron transport characteristics without a substantial increase indriving voltage.

The electron transport region (for example, the electron transport layerin the electron transport region) may further include, in addition tothe materials described above, a metal-containing material.

The metal-containing material may include at least one selected fromalkali metal complex and alkaline earth-metal complex. The alkali metalcomplex may include a metal ion selected from a Li ion, a Na ion, a Kion, a Rb ion, and a Cs ion, and the alkaline earth-metal complex mayinclude a metal ion selected from a Be ion, a Mg ion, a Ca ion, a Srion, and a Ba ion. A ligand coordinated with the metal ion of the alkalimetal complex or the alkaline earth-metal complex may be selected from ahydroxy quinoline, a hydroxy isoquinoline, a hydroxy benzoquinoline, ahydroxy acridine, a hydroxy phenanthridine, a hydroxy phenyloxazole, ahydroxy phenylthiazole, a hydroxy diphenyloxadiazole, a hydroxydiphenylthiadiazole, a hydroxy phenylpyridine, a hydroxyphenylbenzimidazole, a hydroxy phenylbenzothiazole, a bipyridine, aphenanthroline, and a cyclopentadiene, but embodiments of the presentdisclosure are not limited thereto.

For example, the metal-containing material may include a Li complex. TheLi complex may include, for example, Compound ET-D1 (lithium quinolate,LiQ) or ET-D2:

The electron transport region may include an electron injection layerthat facilitates injection of electrons from the second electrode 190.The electron injection layer may directly contact the second electrode190.

The electron injection layer may have i) a single-layered structureincluding a single layer including a single material, ii) asingle-layered structure including a single layer including a pluralityof different materials, or iii) a multi-layered structure having aplurality of layers including a plurality of different materials.

The electron injection layer may include an alkali metal, an alkalineearth metal, a rare earth metal, an alkali metal compound, an alkalineearth-metal compound, a rare earth metal compound, an alkali metalcomplex, an alkaline earth-metal complex, a rare earth metal complex, orany combinations thereof.

The alkali metal may be selected from Li, Na, K, Rb, and Cs. In oneembodiment, the alkali metal may be Li, Na, or Cs. In one or moreembodiments, the alkali metal may be Li or Cs, but the inventiveconcepts are not limited thereto.

The alkaline earth metal may be selected from Mg, Ca, Sr, and Ba.

The rare earth metal may be selected from Sc, Y, Ce, Tb, Yb, and Gd.

The alkali metal compound, the alkaline earth-metal compound, and therare earth metal compound may be selected from oxides and halides (forexample, fluorides, chlorides, bromides, or iodides) of the alkalimetal, the alkaline earth-metal, and the rare earth metal.

The alkali metal compound may be selected from alkali metal oxides, suchas Li₂O, Cs₂O, or K₂O, and alkali metal halides, such as LiF, NaF, CsF,KF, LiI, NaI, CsI, or KI. In one embodiment, the alkali metal compoundmay be selected from LiF, Li₂O, NaF, LiI, NaI, CsI, and KI, but theinventive concepts are not limited thereto.

The alkaline earth-metal compound may be selected from alkalineearth-metal oxides, such as BaO, SrO, CaO, Ba_(x)Sr_(1-x)O (0<x<1), orBa_(x)Ca_(1-x)O (0<x<1). In an exemplary embodiment, the alkalineearth-metal compound may be selected from BaO, SrO, and CaO, but theinventive concepts are not limited thereto.

The rare earth metal compound may be selected from YbF₃, ScF₃, ScO₃,Y₂O₃, Ce₂O₃, GdF₃, and TbF₃. In an exemplary embodiment, the rare earthmetal compound may be selected from YbF₃, ScF₃, TbF₃, YbI₃, ScI₃, andTb₃, but the inventive concepts are not limited thereto.

The alkali metal complex, the alkaline earth-metal complex, and the rareearth metal complex may include an ion of alkali metal, alkalineearth-metal, and rare earth metal as described above, and a ligandcoordinated with a metal ion of the alkali metal complex, the alkalineearth-metal complex, or the rare earth metal complex may be selectedfrom hydroxy quinoline, hydroxy isoquinoline, hydroxy benzoquinoline,hydroxy acridine, hydroxy phenanthridine, hydroxy phenyloxazole, hydroxyphenylthiazole, hydroxy diphenyloxadiazole, hydroxy diphenylthiadiazole,hydroxy phenylpyridine, hydroxy phenylbenzimidazole, hydroxyphenylbenzothiazole, bipyridine, phenanthroline, and cyclopentadiene,but the inventive concepts are not limited thereto.

The electron injection layer may consist of an alkali metal, an alkalineearth metal, a rare earth metal, an alkali metal compound, an alkalineearth-metal compound, a rare earth metal compound, an alkali metalcomplex, an alkaline earth-metal complex, a rare earth metal complex, orany combinations thereof, as described above. In one or moreembodiments, the electron injection layer may further include an organicmaterial. When the electron injection layer further includes an organicmaterial, an alkali metal, an alkaline earth metal, a rare earth metal,an alkali metal compound, an alkaline earth-metal compound, a rare earthmetal compound, an alkali metal complex, an alkaline earth-metalcomplex, a rare earth metal complex, or any combinations thereof may behomogeneously or non-homogeneously dispersed in a matrix including theorganic material.

A thickness of the electron injection layer may be in a range of about 1Å to about 100 Å, for example, about 3 Å to about 90 Å. When thethickness of the electron injection layer is within the range describedabove, the electron injection layer may have satisfactory electroninjection characteristics without a substantial increase in drivingvoltage.

[Second Electrode 190]

The second electrode 190 may be on the organic layer having such astructure. The second electrode 190 may be a cathode, which is anelectron injection electrode, and in this regard, a material for formingthe second electrode 190 may be selected from metal, an alloy, anelectrically conductive compound, and a combination thereof, which havea relatively low work function.

The second electrode 190 may include at least one selected from lithium(Li), silver (Ag), magnesium (Mg), aluminum (Al), aluminum-lithium(Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver(Mg—Ag), ITO, and IZO, but the inventive concepts are not limitedthereto. The second electrode 190 may be a transmissive electrode, asemi-transmissive electrode, or a reflective electrode.

The second electrode 190 may have a single-layered structure, or amulti-layered structure including two or more layers.

The organic light-emitting device 10, 20, or 30 may further include acapping layer in a direction in which light is extracted. The cappinglayer may serve to improve external luminescent efficiency as a resultof the principle of constructive interference

The capping layer may be an organic capping layer including an organicmaterial, an inorganic layer including an inorganic material, or acomposite capping layer including an organic material and an inorganicmaterial.

The capping layer may include at least one material selected from acarbocyclic compound, a heterocyclic compound, an amine-based compound,porphine derivatives, phthalocyanine derivatives, naphthalocyaninederivatives, an alkali metal complex, and an alkaline earth metalcomplex. The carbocyclic compound, the heterocyclic compound, and theamine-based compound may be substituted with a substituent including atleast one element selected from O, N, S, Se, Si, F, Cl, Br, and I.

In an exemplary embodiment, the capping layer may include an amine-basedto compound.

In one or more exemplary embodiments, the capping layer may include acompound represented by Formula 201 or a compound represented by Formula202.

In one or more exemplary embodiments, the capping layer may be selectedfrom Compounds HT28 to HT33 and Compounds CP1 to CP5, but the inventiveconcepts are not limited thereto.

Hereinbefore, the organic light-emitting device according to anembodiment has been described in connection with FIGS. 1 to 3. However,the inventive concepts are not limited thereto.

Layers constituting the hole transport region, an emission layer, andlayers constituting the electron transport region may be formed in acertain region by using one or more suitable methods selected fromvacuum deposition, spin coating, casting, Langmuir-Blodgett (LB)deposition, ink-jet printing, laser-printing, and laser-induced thermalimaging.

When layers constituting the hole transport region, an emission layer,and layers constituting the electron transport region are formed byvacuum deposition, the deposition may be performed at a depositiontemperature of about 100° C. to about 500° C., a vacuum degree of about10⁻⁸ torr to about 10⁻³ torr, and a deposition speed of about 0.01 Å/secto about 100 Å/sec by taking into account a material to be included in alayer to be formed, and the structure of a layer to be formed.

When layers constituting the hole transport region, an emission layer,and layers constituting the electron transport region are formed by spincoating, the spin coating may be performed at a coating speed of about2,000 rpm to about 5,000 rpm and at a heat treatment temperature ofabout 80° C. to about 200° C. by taking into account a material to beincluded in a layer to be formed, and the structure of a layer to beformed.

[General Definition of Substituents]

The term “C₁-C₆₀ alkyl group”, as used herein, refers to a linear orbranched aliphatic saturated hydrocarbon monovalent group having 1 to 60carbon atoms, and examples thereof include a methyl group, an ethylgroup, a propyl group, an isobutyl group, a sec-butyl group, atert-butyl group, a pentyl group, an isoamyl group, and a hexyl group.The term “C₁-C₆₀ alkylene group”, as used herein, refers to a divalentgroup having the same structure as the C₁-C₆₀ alkyl group.

The term “C₂-C₆₀ alkenyl group”, as used herein, refers to a hydrocarbongroup having at least one carbon-carbon double bond in the middle or atthe terminus of the C₂-C₆₀ alkyl group, and examples thereof include anethenyl group, a propenyl group, and a butenyl group. The term “C₂-C₆₀alkenylene group”, as used herein, refers to a divalent group having thesame structure as the C₂-C₆₀ alkenyl group.

The term “C₂-C₆₀ alkynyl group”, as used herein, refers to a hydrocarbongroup having at least one carbon-carbon triple bond in the middle or atthe terminus of the C₂-C₆₀ alkyl group, and examples thereof include anethynyl group, and a propynyl group. The term “C₂-C₆₀ alkynylene group”,as used herein, refers to a divalent group having the same structure asthe C₂-C₆₀ alkynyl group.

The term “C₁-C₆₀ alkoxy group”, as used herein, refers to a monovalentgroup represented by —OA₁₀₁ (wherein A₁₀₁ is the C₁-C₆₀ alkyl group),and examples thereof include a methoxy group, an ethoxy group, and anisopropyloxy group.

The term “C₃-C₁₀ cycloalkyl group”, as used herein, refers to amonovalent saturated hydrocarbon monocyclic group having 3 to 10 carbonatoms, and examples thereof include a cyclopropyl group, a cyclobutylgroup, a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group.The term “C₃-C₁₀ cycloalkylene group”, as used herein, refers to adivalent group having the same structure as the C₃-C₁₀ cycloalkyl group.

The term “C₁-C₁₀ heterocycloalkyl group”, as used herein, refers to amonovalent monocyclic group having at least one heteroatom selected fromN, O, Si, P, and S as a ring-forming atom and 1 to 10 carbon atoms, andexamples thereof include a 1,2,3,4-oxatriazolidinyl group, atetrahydrofuranyl group, and a tetrahydrothiophenyl group. The term“C₁-C₁₀ heterocycloalkylene group”, as used herein, refers to a divalentgroup having the same structure as the C₁-C₁₀ heterocycloalkyl group.

The term “C₃-C₁₀ cycloalkenyl group”, as used herein, refers to amonovalent monocyclic group that has 3 to 10 carbon atoms and at leastone carbon-carbon double bond in the ring thereof and no aromaticity,and examples thereof include a cyclopentenyl group, a cyclohexenylgroup, and a cycloheptenyl group. The term “C₃-C₁₀ cycloalkenylenegroup”, as used herein, refers to a divalent group having the samestructure as the C₃-C₁₀ cycloalkenyl group.

The term “C₁-C₁₀ heterocycloalkenyl group”, as used herein, refers to amonovalent monocyclic group that has at least one heteroatom selectedfrom N, O, Si, P, and S as a ring-forming atom, 1 to 10 carbon atoms,and at least one carbon-carbon double bond in its ring. Non-limitingexamples of the C₁-C₁₀ heterocycloalkenyl group include a4,5-dihydro-1,2,3,4-oxatriazolyl group, a 2,3-dihydrofuranyl group, anda 2,3-dihydrothiophenyl group. The term “C₁-C₁₀ heterocycloalkenylenegroup”, as used herein, refers to a divalent group having the samestructure as the C₁-C₁₀ heterocycloalkenyl group.

The term “C₆-C₆₀ aryl group”, as used herein, refers to a monovalentgroup having a carbocyclic aromatic system having 6 to 60 carbon atoms,and a C₆-C₆₀ arylene group used herein refers to a divalent group havinga carbocyclic aromatic system having 6 to 60 carbon atoms. Non-limitingexamples of the C₆-C₆₀ aryl group include a phenyl group, a naphthylgroup, an anthracenyl group, a phenanthrenyl group, a pyrenyl group, anda chrysenyl group. When the C₆-C₆₀ aryl group and the C₆-C₆₀ arylenegroup each include two or more rings, the rings may be fused to eachother.

The term “C₁-C₆₀ heteroaryl group”, as used herein refers to amonovalent group having a carbocyclic aromatic system that has at leastone heteroatom selected from N, O, Si, P, and S as a ring-forming atom,in addition to 1 to 60 carbon atoms. The term “C₁-C₆₀ heteroarylenegroup”, as used herein, refers to a divalent group having a carbocyclicaromatic system that has at least one heteroatom selected from N, O, Si,P, and S as a ring-forming atom, in addition to 1 to 60 carbon atoms.Non-limiting examples of the C₁-C₆₀ heteroaryl group include a pyridinylgroup, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, atriazinyl group, a quinolinyl group, and an isoquinolinyl group. Whenthe C₁-C₆₀ heteroaryl group and the C₁-C₆₀ heteroarylene group eachinclude two or more rings, the rings may be condensed with each other.

The term “C₆-C₆₀ aryloxy group”, as used herein refers to —OA₁₀₂(wherein A₁₀₂ is the C₆-C₆₀ aryl group), and the term “C₆-C₆₀ arylthiogroup”, as used herein, indicates —SA₁₀₃ (wherein A₁₀₃ is the C₆-C₆₀aryl group).

The term “monovalent non-aromatic condensed polycyclic group”, as usedherein, refers to a monovalent group (for example, having 8 to 60 carbonatoms) having two or more rings condensed with each other, only carbonatoms as ring-forming atoms, and no aromaticity in its entire molecularstructure. A detailed example of the monovalent non-aromatic condensedpolycyclic group is a fluorenyl group. The term “divalent non-aromaticcondensed polycyclic group”, as used herein refers to a divalent grouphaving the same structure as the monovalent non-aromatic condensedpolycyclic group.

The term “monovalent non-aromatic condensed heteropolycyclic group” asused herein refers to a monovalent group (for example, having 1 to 60carbon atoms) having two or more rings condensed to each other, at leastone heteroatom selected from N, O, Si, P, and S, other than carbonatoms, as a ring-forming atom, and no aromaticity in its entiremolecular structure. An example of the monovalent non-aromatic condensedheteropolycyclic group is a carbazolyl group. The term “divalentnon-aromatic condensed heteropolycyclic group”, as used herein, refersto a divalent group having the same structure as the monovalentnon-aromatic condensed heteropolycyclic group.

The term “C₄-C₆₀ carbocyclic group”, as used herein, refers to amonocyclic or polycyclic group having 4 to 60 carbon atoms in which aring-forming atom is a carbon atom only. The C₄-C₆₀ carbocyclic groupmay be an aromatic carbocyclic group or a non-aromatic carbocyclicgroup. The C₄-C₆₀ carbocyclic group may be a ring, such as benzene, amonovalent group, such as a phenyl group, or a divalent group, such as aphenylene group. In one or more embodiments, depending on the number ofsubstituents connected to the C₄-C₆₀ carbocyclic group, the C₄-C₆₀carbocyclic group may be a trivalent group or a quadrivalent group.

The term “C₂-C₆₀ heterocyclic group”, as used herein, refers to a grouphaving the same structure as the C₄-C₆₀ carbocyclic group, except thatas a ring-forming atom, at least one heteroatom selected from N, O, Si,P, and S is used in addition to carbon (the number of carbon atoms maybe in a range of 2 to 60).

In the present specification, at least one substituent of thesubstituted C₄-C₆₀ carbocyclic group, the substituted C₂-C₆₀heterocyclic group, the substituted C₃-C₁₀ cycloalkylene group, thesubstituted C₁-C₁₀ heterocycloalkylene group, the substituted C₃-C₁₀cycloalkenylene group, the substituted C₁-C₁₀ heterocycloalkenylenegroup, the substituted C₆-C₆₀ arylene group, the substituted C₁-C₆₀heteroarylene group, the substituted divalent non-aromatic condensedpolycyclic group, the substituted divalent non-aromatic condensed toheteropolycyclic group, the substituted C₁-C₆₀ alkyl group, thesubstituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀ alkynyl group,the substituted C₁-C₆₀ alkoxy group, the substituted C₃-C₁₀ cycloalkylgroup, the substituted C₁-C₁₀ heterocycloalkyl group, the substitutedC₃-C₁₀ cycloalkenyl group, the substituted C₁-C₁₀ heterocycloalkenylgroup, the substituted C₆-C₆₀ aryl group, the substituted C₆-C₆₀ aryloxygroup, the substituted C₆-C₆₀ arylthio group, the substituted C₁-C₆₀heteroaryl group, the substituted monovalent non-aromatic condensedpolycyclic group, and the substituted monovalent non-aromatic condensedheteropolycyclic group may be selected from: deuterium, —F, —Cl, —Br,—I, a hydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group; aC₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, anda C₁-C₆₀ alkoxy group, each substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenylgroup, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, amonovalent non-aromatic condensed polycyclic group, a monovalentnon-aromatic condensed heteropolycyclic group, —Si(Q₁₁)(Q₁₂)(Q₁₃),—N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁), —S(═O)₂(Q₁₁), and—P(═O)(Q₁₁)(Q₁₂); a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkylgroup, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, aC₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, aC₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclicgroup, and a monovalent non-aromatic condensed heteropolycyclic group; aC₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,and a monovalent non-aromatic condensed heteropolycyclic group, eachsubstituted with at least one selected from deuterium, —F, —Cl, —Br, —I,a hydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenylgroup, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, amonovalent non-aromatic condensed polycyclic group, a monovalentnon-aromatic condensed heteropolycyclic group, —Si(Q₂₁)(Q₂₂)(Q₂₃),—N(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), and—P(═O)(Q₂₁)(Q₂₂); and —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂),—C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), and Q₁₁ to Q₁₃, Q₂₁ toQ₂₃, and Q₃₁ to Q₃₃ may each independently be selected from hydrogen,deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkylgroup, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, aC₆-C₆₀ aryl group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromaticcondensed polycyclic group, a monovalent non-aromatic condensedheteropolycyclic group, a C₁-C₆₀ alkyl group substituted with at leastone selected from deuterium, —F, and a cyano group, a C₆-C₆₀ aryl groupsubstituted with at least one selected from deuterium, —F, and a cyanogroup, a biphenyl group, and a terphenyl group.

The term “Ph” used herein refers to a phenyl group, the term “Me” usedherein refers to a methyl group, the term “Et” used herein refers to anethyl group, the term “ter-Bu” or “Bu^(t)” used herein refers to atert-butyl group, and the term “OMe” used herein refers to a methoxygroup.

The term “biphenyl group”, as used herein, refers to “a phenyl groupsubstituted with a phenyl group”. In other words, the “biphenyl group”is a substituted phenyl group having a C₆-C₆₀ aryl group as asubstituent.

The term “terphenyl group”, as used herein, refers to “a phenyl groupsubstituted with a biphenyl group”. In other words, the “terphenylgroup” is a phenyl group having, as a substituent, a C₆-C₆₀ aryl groupsubstituted with a C₆-C₆₀ aryl group.

* and *′ used herein, unless defined otherwise, each refer to a bindingsite to a neighboring atom in a corresponding formula.

Hereinafter, an organic light-emitting device according to an exemplaryembodiment will be described in detail with reference to SynthesisExamples and Examples.

EXAMPLES Evaluation Example 1: Measurement of Lowest Excitation TripletEnergy Level (T1) Example 1

As a substrate and an anode, a glass substrate with 15 Ω/cm² (500 Å)ITO, which was manufactured by Corning Inc., was cut to a size of 50mm×50 mm×0.7 mm, and the glass substrate was sonicated with isopropylalcohol and pure water each for 5 minutes, and then cleaned by exposureto ultraviolet rays and ozone for 30 minutes. Then, the glass substratewas provided to a vacuum deposition apparatus.

HATCN was vacuum-deposited on the glass substrate to form a holeinjection layer having a thickness of 100 Å, and Tris-PCz wasvacuum-deposited on the hole injection layer to form a hole transportlayer having a thickness of 500 Å.

TCTA was vacuum-deposited on the hole transport layer to form anelectron blocking layer having a thickness of 50 Å.

H57 (host) and DABNA-1 (dopant) were co-deposited on the electronblocking layer at a weight ratio of 99:1 to form an emission layerhaving a thickness of 200 Å.

Compound 28 was vacuum-deposited on the emission layer to form a holeblocking layer having a thickness of 50 Å.

BPy-DP2 was vacuum-deposited on the hole blocking layer to form anelectron transport layer having a thickness of 300 Å. Yb wasvacuum-deposited on the electron transport layer to form an electroninjection layer having a thickness of 10 Å, and Mg and Al wereco-deposited on the electron injection layer at a weight ratio of 90:10to form a cathode having a thickness of 3,000 Å, thereby completing themanufacture of an organic light-emitting device.

T₁(H): 1.6 eV

T₁(D): 2.53 eV

T₁(BL): 2.8 eV

HOMO(D): −5.2 eV, HOMO(H): −5.4 eV

Example 2

An organic light-emitting device was manufactured in the same manner asin Example 1, except that DABNA-2 was used as a dopant.

T₁(H): 1.6 eV

T₁(D): 2.48 eV

T₁(BL): 2.8 eV

HOMO(D): −5.2 eV, HOMO(H): −5.4 eV

Example 3

As a substrate and an anode, a glass substrate with 15 Ω/cm² (500 Å)ITO, which was manufactured by Corning Inc., was cut to a size of 50mm×50 mm×0.7 mm, and the glass substrate was sonicated with isopropylalcohol and pure water each for 5 minutes, and then cleaned by exposureto ultraviolet rays and ozone for 30 minutes. Then, the glass substratewas provided to a vacuum deposition apparatus.

HATCN was vacuum-deposited on the glass substrate to form a holeinjection layer having a thickness of 100 Å, and Tris-PCz wasvacuum-deposited on the hole injection layer to form a hole transportlayer having a thickness of 500 Å.

TCTA was vacuum-deposited on the hole transport layer to form anelectron blocking layer having a thickness of 50 Å.

H57 (host) and 4CZIPN (dopant) were co-deposited on the electronblocking layer at a weight ratio of 90:10 to form an emission layerhaving a thickness of 200 Å.

Compound 28 was vacuum-deposited on the emission layer to form a holeblocking layer having a thickness of 50 Å.

BPy-DP2 was vacuum-deposited on the hole blocking layer to form anelectron transport layer having a thickness of 300 Å. Yb wasvacuum-deposited on the electron transport layer to form an electroninjection layer having a thickness of 10 Å, and Mg and Al wereco-deposited on the electron injection layer at a weight ratio of 90:10to form a cathode having a thickness of 3,000 Å, thereby completing themanufacture of an organic light-emitting device.

T₁(H): 1.6 eV

T₁(D): 2.33 eV

T₁(BL): 2.7 eV

LUMO(D): −3.2 eV, LUMO(H): −2.4 eV

Comparative Example 1

An organic light-emitting device was manufactured in the same manner asin Example 1, except that H60 was used as a host in an emission layer.

T₁(H): 1.6 eV; |S₁(H)−T₁(H)|=0.15 eV

T₁(D): 2.53 eV

T₁(BL): 2.7 eV

HOMO(D): −5.2 eV, HOMO(H): −5.4 eV

Comparative Example 2

An organic light-emitting device was manufactured in the same manner asin Example 2, except that H60 was used as a host in an emission layer.

T₁(H): 1.6 eV; |S₁(H)−T₁(H)|=0.14 eV

T₁(D): 2.48 eV

T₁(BL): 2.7 eV

HOMO(D): −5.2 eV, HOMO(H): −5.4 eV

Comparative Example 3

An organic light-emitting device was manufactured in the same manner asin Example 3, except that H60 was used as a host in an emission layer.

T₁(H): 1.6 eV; |S₁(H)−T₁(H)|=0.01 eV

T₁(D): 2.33 eV

T₁(BL): 2.7 eV

LUMO(D): −3.2 eV, LUMO(H): −2.3 eV

Evaluation Example 2

The driving voltage, current efficiency, external quantum efficiency(EQE), and lifespan (T95) of the organic light-emitting devicesmanufactured according to Examples 1 to 3 and Comparative Examples 1 to3 were measured by using Keithley SMU 236 and a luminance meter PR650,and results thereof are shown in Table 1.

TABLE 1 Electron Hole Driving Current blocking Emission layer blockingvoltage efficiency EQE Lifespan layer Dopant Host layer (V) (Cd/A) %(hr) Example 1 TCTA DABNA-1 H57 28 5.0 6 — 30 Example 2 TCTA DABNA-2 H5728 4.3 8 — 40 Example 3 TCTA 4CZIPN H57 28 3.6 25 — 500 Comparative TCTADABNA-1 H60 28 5.5 8 15 1 Example 1 Comparative TCTA DABNA-2 H60 28 5.010 10 0.1 Example 2 Comparative TCTA 4CZIPN H60 28 4.0 30 13 2 Example 3

Example 3

From Table 1, it is confirmed that the organic light-emitting devices ofExamples 1 to 3 have a low driving voltage and a long lifespan, ascompared with those of the organic light-emitting devices of ComparativeExamples 1 to 3.

An organic light-emitting device, which includes the host, the dopant,the blocking material satisfying the lowest excitation triplet energylevel relationship and in which the dopant included in the emissionlayer adjacent to the blocking layer including the blocking material isthe TADF emission dopant, may have a long lifespan and high efficiency.

Although certain exemplary embodiments and implementations have beendescribed herein, other embodiments and modifications will be apparentfrom this description. Accordingly, the inventive concepts are notlimited to such embodiments, but rather to the broader scope of theappended claims and various obvious modifications and equivalentarrangements as would be apparent to a person of ordinary skill in theart.

What is claimed is:
 1. An organic light-emitting device comprising: afirst electrode; a second electrode facing the first electrode; anemission layer between the first electrode and the second electrode; andat least one of an electron blocking layer between the first electrodeand the emission layer and directly contacting the emission layer, and ahole blocking layer between the second electrode and the emission layerand directly contacting the emission layer, wherein: the emission layercomprises a host and a dopant, and the dopant emits delayed tofluorescence or fluorescence; the electron blocking layer or the holeblocking layer comprises a blocking material; and the host, the dopant,and the blocking material satisfy Equation:T ₁(BL)>T ₁(D)>T ₁(H),  Equation 1 wherein, in Equation 1, T₁(BL) is alowest excitation triplet energy level of the blocking material, T₁(D)is a lowest excitation triplet energy level of the dopant, and T₁(H) isa lowest excitation triplet energy level of the host.
 2. The organiclight-emitting device of claim 1, wherein the dopant emits delayedfluorescence.
 3. The organic light-emitting device of claim 1, wherein:the electron blocking layer is only between the first electrode and theemission layer; the hole blocking layer is only between the secondelectrode and the emission layer; or the electron blocking layer isbetween the first electrode and the emission layer, and the holeblocking layer is between the second electrode and the emission layer.4. The organic light-emitting device of claim 1, wherein: when theelectron blocking layer comprises the blocking material, the blockingmaterial is an electron blocking material; and when the hole blockinglayer comprises the blocking material, the blocking material is a holeblocking material.
 5. The organic light-emitting device of claim 1,wherein a thermally activated delayed fluorescence (TADF) emissionregion in the emission layer is present at an interface between theemission layer and the electron blocking layer or at an interfacebetween the emission layer and the hole blocking layer.
 6. The organiclight-emitting device of claim 1, wherein the dopant is a hole trappingdopant or an electron trapping dopant.
 7. The organic light-emittingdevice of claim 6, wherein: when the dopant is the hole trapping dopant,the electron blocking layer is between the first electrode and theemission layer, and the TADF emission region in the emission layer ispresent at the interface between the emission layer and the electronblocking layer, and when the dopant is the electron trapping dopant, thehole blocking layer is between the second electrode and the emissionlayer, and the TADF emission region in the emission layer is present atthe interface between the emission layer and the hole blocking layer. 8.The organic light-emitting device of claim 6, wherein: when the dopantis the hole trapping dopant, a highest occupied molecular orbital (HOMO)energy level (HOMO(D)) of the dopant and a HOMO energy level (HOMO(H))of the host satisfy |HOMO(H)|>|HOMO(D)|; and when the dopant is theelectron trapping dopant, a lowest unoccupied molecular orbital (LUMO)energy level (LUMO(D)) of the dopant and a LUMO energy level (LUMO(H))of the host satisfy |LUMO(D)≡>|LUMO(H)|.
 9. The organic light-emittingdevice of claim 1, wherein the host, the dopant, and the blockingmaterial further satisfy one or more selected from Equations 1-1 and1-2:1.0 eV>T ₁(BL)−T ₁(D)>0.01 eV  Equation 1-11.0 eV>T ₁(D)−T ₁(H)>0.01 eV.  Equation 1-2
 10. The organiclight-emitting device of claim 1, wherein the host, the dopant, and theblocking material further satisfy one or more selected from Equations1-11 and 1-12:HOMO (D)>HOMO (H)+0.1 eV  Equation 1-11|LUMO (D)|>|LUMO (H)|+0.1 eV.  Equation 1-12
 11. The organiclight-emitting device of claim 1, wherein bonding energy betweenmolecules of the blocking material is lower than bonding energy betweenmolecules of the host or the dopant.
 12. The organic light-emittingdevice of claim 1, wherein: the host comprises a compound represented byFormula 301:[Ar₃₀₁]_(xb11)-[(L₃₀₁)_(xb1)-R₃₁]_(xb21),  Formula 301 wherein, inFormula 301, Ar₃₀₁ is a substituted or unsubstituted C₅-C₆₀ carbocyclicgroup or a substituted or unsubstituted C₁-C₆₀ heterocyclic group, xb11is 1, 2, or 3, L₃₀₁ is selected from a substituted or unsubstitutedC₃-C₁₀ cycloalkylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylenegroup, a substituted or unsubstituted divalent non-aromatic condensedpolycyclic group, and a substituted or unsubstituted divalentnon-aromatic condensed heteropolycyclic group, xb1 is an integer from 0to 5, R₃₀₁ is selected from deuterium, —F, —Cl, —Br, —I, a hydroxylgroup, a cyano group, a nitro group, an amidino group, a hydrazinogroup, a hydrazono group, a substituted or unsubstituted C₁-C₆₀ alkylgroup, a substituted or unsubstituted C₂-C₆₀ alkenyl group, asubstituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted orunsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylgroup, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, asubstituted or unsubstituted C₆-C₆₀ aryl group, a substituted orunsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstitutedC₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroarylgroup, a substituted or unsubstituted monovalent non-aromatic condensedpolycyclic group, a substituted or unsubstituted monovalent non-aromaticcondensed heteropolycyclic group, —Si(Q₃₀₁)(Q₃₀₂)(Q₃₀₃), —N(Q₃₀₁)(Q₃₀₂),—B(Q₃₀₁)(Q₃₀₂), —C(═O)(Q₃₀₁), —S(═O)₂(Q₃₀₁), and —P(═O)(Q₃₀₁)(Q₃₀₂),xb21 is an integer from 1 to 5, and Q₃₀₁ to Q₃₀₃ are each independentlyselected from a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a phenylgroup, a biphenyl group, a terphenyl group, and a naphthyl group, butembodiments of the present disclosure are not limited thereto.
 13. Theorganic light-emitting device of claim 1, wherein the dopant comprises acompound represented by Formula 2:

wherein, in Formula 2, X₁₁ is selected from O, S, N(R₁₃), andC(R₁₃)(R₁₄), X₁₂ is selected from a single bond, O, S, N(R₁₅), andC(R₁₅)(R₁₆), A₁₁ and A₁₂ are each independently selected from a C₅-C₆₀carbocyclic group and a C₁-C₆₀ heterocyclic group, R₁₁ to R₁₆ are eachindependently selected from hydrogen, deuterium, —F, —Cl, —Br, —I, ahydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a substituted or unsubstitutedC₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group,a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted orunsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylgroup, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, asubstituted or unsubstituted C₆-C₆₀ aryl group, a substituted orunsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstitutedC₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroarylgroup, a substituted or unsubstituted C₁-C₆₀ heteroaryloxy group, asubstituted or unsubstituted C₁-C₆₀ heteroarylthio group, a substitutedor unsubstituted monovalent non-aromatic condensed polycyclic group, asubstituted or unsubstituted monovalent non-aromatic condensedheteropolycyclic group, —Si(Q₁)(Q₂)(Q₃), —B(Q₁)(Q₂), —N(Q₁)(Q₂),—P(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)(Q₁), —S(═O)₂(Q₁), —P(═O)(Q₁)(Q₂), and—P(═S)(Q₁)(Q₂), b11 and b12 are each independently selected from 1, 2,3, 4, 5, and 6, and Q₁ to Q₃ are each independently selected fromhydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group,a nitro group, an amidino group, a hydrazino group, a hydrazono group, aC₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, aC₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, aC₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a C₁-C₆₀ heteroaryloxygroup, a C₁-C₆₀ heteroarylthio group, a monovalent non-aromaticcondensed polycyclic group, a monovalent non-aromatic condensedheteropolycyclic group, a biphenyl group, and a terphenyl group.
 14. Theorganic light-emitting device of claim 1, wherein the dopant comprises acompound represented by Formula 3:

wherein, in Formula 3, X₂₁ is N or C(R₂₁), X₂₂ is N or C(R₂₂), X₂₃ is Nor C(R₂₃), X₂₄ is N or C(R₂₄), X₂₅ is N or C(R₂₅), and X₂₆ is N orC(R₂₆), wherein at least one selected from X₂₁ to X₂₆ is N, R₂₁ to R₂₆are each independently selected from hydrogen, deuterium, a substitutedor unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstitutedC₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalentnon-aromatic condensed polycyclic group, and a substituted orunsubstituted monovalent non-aromatic condensed heteropolycyclic group,and at least one selected from R₂₁ to R₂₆ is selected from a substitutedor unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstitutedC₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalentnon-aromatic condensed polycyclic group, and a substituted orunsubstituted monovalent non-aromatic condensed heteropolycyclic group.15. The organic light-emitting device of claim 1, wherein the electronblocking layer comprises a blocking material, and the blocking materialcomprises a compound represented by Formula 2:

wherein, in Formula 2, X₁₁ is selected from O, S, N(R₁₃), andC(R₁₃)(R₁₄), X₁₂ is selected from a single bond, O, S, N(R₁₅), andC(R₁₅)(R₁₆), A₁₁ and A₁₂ are each independently selected from a C₅-C₆₀carbocyclic group and a C₁-C₆₀ heterocyclic group, R₁₁ to R₁₆ are eachindependently selected from hydrogen, deuterium, —F, —Cl, —Br, —I, ahydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a substituted or unsubstitutedC₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group,a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted orunsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylgroup, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, asubstituted or unsubstituted C₆-C₆₀ aryl group, a substituted orunsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstitutedC₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroarylgroup, a substituted or unsubstituted C₁-C₆₀ heteroaryloxy group, asubstituted or unsubstituted C₁-C₆₀ heteroarylthio group, a substitutedor unsubstituted monovalent non-aromatic condensed polycyclic group, asubstituted or unsubstituted monovalent non-aromatic condensedheteropolycyclic group, —Si(Q₁)(Q₂)(Q₃), —B(Q₁)(Q₂), —N(Q₁)(Q₂),—P(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)(Q₁), —S(═O)₂(Q₁), —P(═O)(Q₁)(Q₂), and—P(═S)(Q₁)(Q₂), b11 and b12 are each independently selected from 1, 2,3, 4, 5, and 6, and Q₁ to Q₃ are each independently selected fromhydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group,a nitro group, an amidino group, a hydrazino group, a hydrazono group, aC₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, aC₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, aC₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a C₁-C₆₀ heteroaryloxygroup, a C₁-C₆₀ heteroarylthio group, a monovalent non-aromaticcondensed polycyclic group, a monovalent non-aromatic condensedheteropolycyclic group, a biphenyl group, and a terphenyl group.
 16. Theorganic light-emitting device of claim 1, wherein the hole blockinglayer comprises a blocking material, and the blocking material comprisesa compound represented by Formula 3:

wherein, in Formula 3, X₂₁ is N or C(R₂₁), X₂₂ is N or C(R₂₂), X₂₃ is Nor C(R₂₃), X₂₄ is N or C(R₂₄), X₂₅ is N or C(R₂₅), and X₂₆ is N orC(R₂₆), wherein at least one selected from X₂₁ to X₂₆ is N, R₂₁ to R₂₆are each independently selected from hydrogen, deuterium, a substitutedor unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstitutedC₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalentnon-aromatic condensed polycyclic group, and a substituted orunsubstituted monovalent non-aromatic condensed heteropolycyclic group,and at least one selected from R₂₁ to R₂₆ is selected from a substitutedor unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstitutedC₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalentnon-aromatic condensed polycyclic group, and a substituted orunsubstituted monovalent non-aromatic condensed heteropolycyclic group.17. The organic light-emitting device of claim 1, wherein: the organiclight-emitting device further comprises a hole transport region betweenthe first electrode and the emission layer; and the hole transportregion comprises a hole transport material.
 18. The organiclight-emitting device of claim 1, wherein: the organic light-emittingdevice further comprises an electron transport region between theemission layer and the second electrode; and the electron transportregion comprises an electron transport material.
 19. The organiclight-emitting device of claim 1, wherein a ratio of a delayedfluorescence component to total emission components emitted from theemission layer is greater than or equal to 50%.
 20. A display apparatuscomprising: a thin-film transistor comprising a source electrode, adrain electrode, and an active layer; and the organic light-emittingdevice of claim 1, wherein the first electrode of the organiclight-emitting device is electrically connected to one selected from thesource electrode and the drain electrode of the thin-film transistor.